//------------------------------------------------------------------------------
// <copyright file="OdbcMetaDataFactory.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
//
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
//
//------------------------------------------------------------------------------

namespace System.Data.Odbc{

    using System;
    using System.Data;
    using System.IO;
    using System.Collections;
    using System.Data.Common;
    using System.Xml;
    using System.Xml.Schema;
    using System.Diagnostics;
    using System.Data.ProviderBase;
    using System.Text;


    internal class OdbcMetaDataFactory : DbMetaDataFactory{

        private struct SchemaFunctionName {
            internal SchemaFunctionName(string schemaName, ODBC32.SQL_API odbcFunction) {
                _schemaName = schemaName;
                _odbcFunction = odbcFunction;
            }
            internal readonly string          _schemaName;
            internal readonly ODBC32.SQL_API  _odbcFunction;
        }

        private const string _collectionName = "CollectionName";
        private const string _populationMechanism = "PopulationMechanism";
        private const string _prepareCollection = "PrepareCollection";

        private readonly SchemaFunctionName[] _schemaMapping;

        static internal readonly char[] KeywordSeparatorChar = new char[1] { ',' };


        internal OdbcMetaDataFactory(Stream XMLStream,
                                   string serverVersion,
                                   string serverVersionNormalized,
                                   OdbcConnection connection):
            base(XMLStream, serverVersion, serverVersionNormalized) {

            // set up the colletion name ODBC function mapping guid mapping
            _schemaMapping = new SchemaFunctionName[] {

                new SchemaFunctionName(DbMetaDataCollectionNames.DataTypes,ODBC32.SQL_API.SQLGETTYPEINFO),
                new SchemaFunctionName(OdbcMetaDataCollectionNames.Columns,ODBC32.SQL_API.SQLCOLUMNS),
                new SchemaFunctionName(OdbcMetaDataCollectionNames.Indexes,ODBC32.SQL_API.SQLSTATISTICS),
                new SchemaFunctionName(OdbcMetaDataCollectionNames.Procedures,ODBC32.SQL_API.SQLPROCEDURES),
                new SchemaFunctionName(OdbcMetaDataCollectionNames.ProcedureColumns,ODBC32.SQL_API.SQLPROCEDURECOLUMNS),
                new SchemaFunctionName(OdbcMetaDataCollectionNames.ProcedureParameters,ODBC32.SQL_API.SQLPROCEDURECOLUMNS),
                new SchemaFunctionName(OdbcMetaDataCollectionNames.Tables,ODBC32.SQL_API.SQLTABLES),
                new SchemaFunctionName(OdbcMetaDataCollectionNames.Views,ODBC32.SQL_API.SQLTABLES)};

            // verify the existence of the table in the data set
            DataTable metaDataCollectionsTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.MetaDataCollections];
            if (metaDataCollectionsTable == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.MetaDataCollections);
            }

            // copy the table filtering out any rows that don't apply to the current version of the provider
            metaDataCollectionsTable = CloneAndFilterCollection(DbMetaDataCollectionNames.MetaDataCollections, null);

            // verify the existence of the table in the data set
            DataTable restrictionsTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.Restrictions];
            if (restrictionsTable != null){
                // copy the table filtering out any rows that don't apply to the current version of the provider
                restrictionsTable= CloneAndFilterCollection(DbMetaDataCollectionNames.Restrictions, null);
            }

            // need to filter out any of the collections where
            // 1) it is populated using prepare collection
            // 2) it is in the collection to odbc function mapping above
            // 3) the provider does not support the necessary odbc function


            DataColumn populationMechanism = metaDataCollectionsTable.Columns[_populationMechanism];
            DataColumn collectionName = metaDataCollectionsTable.Columns[_collectionName];
            DataColumn restrictionCollectionName = null;
            if (restrictionsTable != null){
                restrictionCollectionName = restrictionsTable.Columns[_collectionName];
            }

            foreach (DataRow collection in metaDataCollectionsTable.Rows){
                if ((string)collection[populationMechanism] == _prepareCollection) {
                    // is the collection in the mapping
                    int mapping = -1;
                    for (int i = 0; i < _schemaMapping.Length; i++){
                        if (_schemaMapping[i]._schemaName == (string)collection[collectionName]){
                           mapping = i;
                           break;
                        }
                    }
                    // no go on to the next collection
                    if (mapping == -1) {
                        continue;
                    }

                    // does the provider support the necessary odbc function
                    // if not delete the row from the table
                    if (connection.SQLGetFunctions(_schemaMapping[mapping]._odbcFunction) == false){
                        // but first delete any related restrictions
                        if (restrictionsTable != null) {
                            foreach (DataRow restriction in restrictionsTable.Rows) {
                                if ((string)collection[collectionName]==(string)restriction[restrictionCollectionName]) {
                                    restriction.Delete();
                                }
                            }
                            restrictionsTable.AcceptChanges();
                        }
                        collection.Delete();
                    }

                }
            }

            // replace the original table with the updated one
            metaDataCollectionsTable.AcceptChanges();
            CollectionDataSet.Tables.Remove(CollectionDataSet.Tables[DbMetaDataCollectionNames.MetaDataCollections]);
            CollectionDataSet.Tables.Add(metaDataCollectionsTable);

            if (restrictionsTable != null) {
                CollectionDataSet.Tables.Remove(CollectionDataSet.Tables[DbMetaDataCollectionNames.Restrictions]);
                CollectionDataSet.Tables.Add(restrictionsTable);
            }

        }

        private object BooleanFromODBC(object odbcSource) {

            if (odbcSource != DBNull.Value){
                //convert to Int32 before doing the comparison
                //some odbc drivers report the odbcSource value as unsigned, in which case we will
                //have upgraded the type to Int32, and thus can't cast directly to short
                if (Convert.ToInt32(odbcSource, null) == 0) 
                {
                    return false;
                }
                else {
                    return true;
                }
            }

            return DBNull.Value;
        }

        private OdbcCommand GetCommand(OdbcConnection connection){

            OdbcCommand command = connection.CreateCommand();

            // You need to make sure you pick up the transaction from the connection,
            // or odd things can happen...
            command.Transaction = connection.LocalTransaction;
            return command;

        }

        private DataTable DataTableFromDataReader(IDataReader reader, string tableName) {

            // set up the column structure of the data table from the reader
            object[] values;
            DataTable resultTable = NewDataTableFromReader(reader, out values, tableName);

            // populate the data table from the data reader
            while (reader.Read()) {
                reader.GetValues(values);
                resultTable.Rows.Add(values);
            }
            return resultTable;
        }

        private void DataTableFromDataReaderDataTypes(DataTable dataTypesTable, OdbcDataReader dataReader, OdbcConnection connection) {

            DataTable       schemaTable = null;
            // 

            // Build a DataTable from the reader
            schemaTable = dataReader.GetSchemaTable();

            // vstfdevdiv:479715 Handle cases where reader is empty
            if (null == schemaTable) {
                throw ADP.OdbcNoTypesFromProvider();
            }
            
            object[] getTypeInfoValues = new object[schemaTable.Rows.Count];
            DataRow dataTypesRow;

            DataColumn typeNameColumn = dataTypesTable.Columns[DbMetaDataColumnNames.TypeName];
            DataColumn providerDbTypeColumn = dataTypesTable.Columns[DbMetaDataColumnNames.ProviderDbType];
            DataColumn columnSizeColumn = dataTypesTable.Columns[DbMetaDataColumnNames.ColumnSize];
            DataColumn createParametersColumn = dataTypesTable.Columns[DbMetaDataColumnNames.CreateParameters];
            DataColumn dataTypeColumn = dataTypesTable.Columns[DbMetaDataColumnNames.DataType];
            DataColumn isAutoIncermentableColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsAutoIncrementable];
            DataColumn isCaseSensitiveColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsCaseSensitive];
            DataColumn isFixedLengthColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsFixedLength];
            DataColumn isFixedPrecisionScaleColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsFixedPrecisionScale];
            DataColumn isLongColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsLong];
            DataColumn isNullableColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsNullable];
            DataColumn isSearchableColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsSearchable];
            DataColumn isSearchableWithLikeColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsSearchableWithLike];
            DataColumn isUnsignedColumn = dataTypesTable.Columns[DbMetaDataColumnNames.IsUnsigned];
            DataColumn maximumScaleColumn = dataTypesTable.Columns[DbMetaDataColumnNames.MaximumScale];
            DataColumn minimumScaleColumn = dataTypesTable.Columns[DbMetaDataColumnNames.MinimumScale];
            DataColumn literalPrefixColumn = dataTypesTable.Columns[DbMetaDataColumnNames.LiteralPrefix];
            DataColumn literalSuffixColumn = dataTypesTable.Columns[DbMetaDataColumnNames.LiteralSuffix];
            DataColumn SQLTypeNameColumn = dataTypesTable.Columns[OdbcMetaDataColumnNames.SQLType];


            const int indexTYPE_NAME = 0;
            const int indexDATA_TYPE = 1;
            const int indexCOLUMN_SIZE = 2;
            const int indexCREATE_PARAMS = 5;
            const int indexAUTO_UNIQUE_VALUE = 11;
            const int indexCASE_SENSITIVE = 7;
            const int indexFIXED_PREC_SCALE = 10;
            const int indexNULLABLE = 6;
            const int indexSEARCHABLE = 8;
            const int indexUNSIGNED_ATTRIBUTE = 9;
            const int indexMAXIMUM_SCALE = 14;
            const int indexMINIMUM_SCALE = 13;
            const int indexLITERAL_PREFIX = 3;
            const int indexLITERAL_SUFFIX = 4;

            const int SQL_DATE_V2 = 9;
            const int SQL_TIME_V2 = 10;

            TypeMap typeMap ;


            while (dataReader.Read()) {
                dataReader.GetValues(getTypeInfoValues);
                dataTypesRow = dataTypesTable.NewRow();

                ODBC32.SQL_TYPE sqlType;

                dataTypesRow[typeNameColumn] = getTypeInfoValues[indexTYPE_NAME];
                dataTypesRow[SQLTypeNameColumn] = getTypeInfoValues[indexDATA_TYPE];

                sqlType = (ODBC32.SQL_TYPE)(Int32) Convert.ChangeType(getTypeInfoValues[indexDATA_TYPE],
                                                                      typeof(Int32), 
                                                                      (System.IFormatProvider)null);
                // if the driver is pre version 3 and it returned the v2 SQL_DATE or SQL_TIME types they need
                // to be mapped to thier v3 equlivants
                if (connection.IsV3Driver == false) {
                    if ((int)sqlType == SQL_DATE_V2) {
                        sqlType = ODBC32.SQL_TYPE.TYPE_DATE;
                    }
                    else if ((int)sqlType == SQL_TIME_V2) {
                        sqlType = ODBC32.SQL_TYPE.TYPE_TIME;
                    }
                }
                try {
                   typeMap = TypeMap.FromSqlType(sqlType);
                }
                // FromSqlType will throw an argument exception if it does not recognize the SqlType.
                // This is not an error since the GetTypeInfo DATA_TYPE may be a SQL data type or a driver specific
                // type. If there is no TypeMap for the type its not an error but it will degrade our level of
                // understanding of/ support for the type.
                catch (ArgumentException) {
                    typeMap = null;
                }

                // if we have a type map we can determine the dbType and the CLR type if not leave them null
                if (typeMap != null) {
                    dataTypesRow[providerDbTypeColumn] = typeMap._odbcType;
                    dataTypesRow[dataTypeColumn] = typeMap._type.FullName;
                    // setting isLong and isFixedLength only if we have a type map because for provider
                    // specific types we have no idea what the types attributes are if GetTypeInfo did not
                    // tell us
                    switch (sqlType) {

                        case ODBC32.SQL_TYPE.LONGVARCHAR:
                        case ODBC32.SQL_TYPE.WLONGVARCHAR:
                        case ODBC32.SQL_TYPE.LONGVARBINARY:
                        case ODBC32.SQL_TYPE.SS_XML:
                            dataTypesRow[isLongColumn] = true;
                            dataTypesRow[isFixedLengthColumn] = false;
                            break;

                        case ODBC32.SQL_TYPE.VARCHAR:
                        case ODBC32.SQL_TYPE.WVARCHAR:
                        case ODBC32.SQL_TYPE.VARBINARY:
                            dataTypesRow[isLongColumn] = false;
                            dataTypesRow[isFixedLengthColumn] = false;
                            break;

                        case ODBC32.SQL_TYPE.CHAR:
                        case ODBC32.SQL_TYPE.WCHAR:
                        case ODBC32.SQL_TYPE.DECIMAL:
                        case ODBC32.SQL_TYPE.NUMERIC:
                        case ODBC32.SQL_TYPE.SMALLINT:
                        case ODBC32.SQL_TYPE.INTEGER:
                        case ODBC32.SQL_TYPE.REAL:
                        case ODBC32.SQL_TYPE.FLOAT:
                        case ODBC32.SQL_TYPE.DOUBLE:
                        case ODBC32.SQL_TYPE.BIT:
                        case ODBC32.SQL_TYPE.TINYINT:
                        case ODBC32.SQL_TYPE.BIGINT:
                        case ODBC32.SQL_TYPE.TYPE_DATE:
                        case ODBC32.SQL_TYPE.TYPE_TIME:
                        case ODBC32.SQL_TYPE.TIMESTAMP:
                        case ODBC32.SQL_TYPE.TYPE_TIMESTAMP:
                        case ODBC32.SQL_TYPE.GUID:
                        case ODBC32.SQL_TYPE.SS_VARIANT:
                        case ODBC32.SQL_TYPE.SS_UTCDATETIME:
                        case ODBC32.SQL_TYPE.SS_TIME_EX:
                        case ODBC32.SQL_TYPE.BINARY:    
                            dataTypesRow[isLongColumn] = false;
                            dataTypesRow[isFixedLengthColumn] = true;
                            break;

                        case ODBC32.SQL_TYPE.SS_UDT:
                        default:
                            // for User defined types don't know if its long or or if it is
                            // varaible length or not so leave the fields null
                            break;
                    }
                }



                dataTypesRow[columnSizeColumn] = getTypeInfoValues[indexCOLUMN_SIZE];
                dataTypesRow[createParametersColumn] = getTypeInfoValues[indexCREATE_PARAMS];

                if ((getTypeInfoValues[indexAUTO_UNIQUE_VALUE] == DBNull.Value) ||
                    (Convert.ToInt16(getTypeInfoValues[indexAUTO_UNIQUE_VALUE], null) == 0)) {
                    dataTypesRow[isAutoIncermentableColumn] = false;
                }
                else {
                    dataTypesRow[isAutoIncermentableColumn] = true;
                }

                dataTypesRow[isCaseSensitiveColumn] = BooleanFromODBC(getTypeInfoValues[indexCASE_SENSITIVE]);
                dataTypesRow[isFixedPrecisionScaleColumn] = BooleanFromODBC(getTypeInfoValues[indexFIXED_PREC_SCALE]);

                if (getTypeInfoValues[indexNULLABLE] != DBNull.Value) {
                    //Use Convert.ToInt16 instead of direct cast to short because the value will be Int32 in some cases
                    switch ((ODBC32.SQL_NULLABILITY)Convert.ToInt16(getTypeInfoValues[indexNULLABLE], null)) { 

                        case ODBC32.SQL_NULLABILITY.NO_NULLS:
                            dataTypesRow[isNullableColumn] = false;
                            break;

                        case ODBC32.SQL_NULLABILITY.NULLABLE:
                            dataTypesRow[isNullableColumn] = true;
                            break;

                        case ODBC32.SQL_NULLABILITY.UNKNOWN:
                            dataTypesRow[isNullableColumn] = DBNull.Value;
                            break;
                    }
                }

                if ( DBNull.Value != getTypeInfoValues[indexSEARCHABLE]){

                    //Use Convert.ToInt16 instead of direct cast to short because the value will be Int32 in some cases
                    Int16 searchableValue = Convert.ToInt16(getTypeInfoValues[indexSEARCHABLE], null);
                    switch (searchableValue){

                        case (Int16)ODBC32.SQL_SEARCHABLE.UNSEARCHABLE:
                            dataTypesRow[isSearchableColumn] = false;
                            dataTypesRow[isSearchableWithLikeColumn] = false;
                            break;

                        case (Int16)ODBC32.SQL_SEARCHABLE.LIKE_ONLY:
                             dataTypesRow[isSearchableColumn] = false;
                             dataTypesRow[isSearchableWithLikeColumn] = true;
                             break;

                        case (Int16)ODBC32.SQL_SEARCHABLE.ALL_EXCEPT_LIKE:
                            dataTypesRow[isSearchableColumn] = true;
                            dataTypesRow[isSearchableWithLikeColumn] = false;
                            break;

                        case (Int16)ODBC32.SQL_SEARCHABLE.SEARCHABLE:
                            dataTypesRow[isSearchableColumn] = true;
                            dataTypesRow[isSearchableWithLikeColumn] = true;
                            break;
                    }
                }

                dataTypesRow[isUnsignedColumn] = BooleanFromODBC(getTypeInfoValues[indexUNSIGNED_ATTRIBUTE]);

                //For assignment to the DataSet, don't cast the data types -- let the DataSet take care of any conversion
                if (getTypeInfoValues[indexMAXIMUM_SCALE] != DBNull.Value ) {
                    dataTypesRow[maximumScaleColumn] = getTypeInfoValues[indexMAXIMUM_SCALE];
                }

                if (getTypeInfoValues[indexMINIMUM_SCALE] != DBNull.Value ) {
                    dataTypesRow[minimumScaleColumn] = getTypeInfoValues[indexMINIMUM_SCALE];
                }

                if (getTypeInfoValues[indexLITERAL_PREFIX] != DBNull.Value ) {
                    dataTypesRow[literalPrefixColumn] = getTypeInfoValues[indexLITERAL_PREFIX];
                }

                if (getTypeInfoValues[indexLITERAL_SUFFIX] != DBNull.Value ) {
                    dataTypesRow[literalSuffixColumn] = getTypeInfoValues[indexLITERAL_SUFFIX];
                }

                dataTypesTable.Rows.Add(dataTypesRow);
            }

        }

        private DataTable DataTableFromDataReaderIndex(IDataReader reader,
                                                       string tableName,
                                                       string restrictionIndexName) {

            // set up the column structure of the data table from the reader
            object[] values;
            DataTable resultTable = NewDataTableFromReader(reader, out values, tableName);

            // populate the data table from the data reader
            int positionOfType = 6;
            int positionOfIndexName = 5;
            while (reader.Read()) {
                reader.GetValues(values);
                if (IncludeIndexRow(values[positionOfIndexName],
                                    restrictionIndexName,
                                    Convert.ToInt16(values[positionOfType], null)) == true){
                    resultTable.Rows.Add(values);
                }
            }
            return resultTable;
        }

        private DataTable DataTableFromDataReaderProcedureColumns(IDataReader reader, string tableName,Boolean isColumn) {

            // set up the column structure of the data table from the reader
            object[] values;
            DataTable resultTable = NewDataTableFromReader(reader, out values, tableName);

            // populate the data table from the data reader
            int positionOfColumnType = 4;
            while (reader.Read()) {
                reader.GetValues(values);
                // the column type should always be short but need to check just in case
                if (values[positionOfColumnType].GetType() == typeof(short)) {
                    if ((((short)values[positionOfColumnType] == ODBC32.SQL_RESULT_COL) && (isColumn == true)) ||
                        (((short)values[positionOfColumnType] != ODBC32.SQL_RESULT_COL) && (isColumn == false))) {
                        resultTable.Rows.Add(values);
                    }
                }
            }
            return resultTable;
        }

        private DataTable DataTableFromDataReaderProcedures(IDataReader reader, string tableName,Int16 procedureType) {

            // Build a DataTable from the reader

            // set up the column structure of the data table from the reader
            object[] values;
            DataTable resultTable = NewDataTableFromReader(reader, out values, tableName);

            // populate the data table from the data reader
            int positionOfProcedureType = 7;
            while (reader.Read()) {
                reader.GetValues(values);
                // the column type should always be short but need to check just in case its null
                if (values[positionOfProcedureType].GetType() == typeof(short)) {
                    if ((short)values[positionOfProcedureType] == procedureType) {
                        resultTable.Rows.Add(values);
                    }
                }
            }
            return resultTable;
        }

        private void FillOutRestrictions(int restrictionsCount, string[] restrictions, object[] allRestrictions, string collectionName) {

            Debug.Assert(allRestrictions.Length >= restrictionsCount);

            int i = 0;

            // if we have restrictions put them in the restrictions array
            if (restrictions != null) {

                if (restrictions.Length > restrictionsCount) {
                    throw ADP.TooManyRestrictions(collectionName);
                }

                for (i=0; i < restrictions.Length; i++) {
                    if (restrictions[i] != null) {
                        allRestrictions[i] = restrictions[i];
                    }
                }
            }

            // initalize the rest to no restrictions
            for (; i < restrictionsCount; i++) {
                allRestrictions[i] = null;
            }
        }


        private DataTable GetColumnsCollection(String[] restrictions, OdbcConnection connection){

            OdbcCommand command = null;
            OdbcDataReader dataReader =null;
            DataTable resultTable = null;
            const int  columnsRestrictionsCount = 4;

            try {
                command = GetCommand(connection);
                String[] allRestrictions = new string[columnsRestrictionsCount];
                FillOutRestrictions(columnsRestrictionsCount,restrictions,allRestrictions,OdbcMetaDataCollectionNames.Columns);

                dataReader = command.ExecuteReaderFromSQLMethod(allRestrictions, ODBC32.SQL_API.SQLCOLUMNS);

                resultTable = DataTableFromDataReader(dataReader, OdbcMetaDataCollectionNames.Columns);
            }

            finally {
                if (dataReader != null) {
                    dataReader.Dispose();
                };
                if (command != null) {
                    command.Dispose();
                };
            }
            return resultTable;
        }


        private DataTable GetDataSourceInformationCollection(string [] restrictions,
                                                             OdbcConnection connection){

            if (ADP.IsEmptyArray(restrictions) == false) {
               throw ADP.TooManyRestrictions(DbMetaDataCollectionNames.DataSourceInformation);
            }

            // verify that the data source information table is in the data set
            DataTable dataSourceInformationTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.DataSourceInformation];
            if (dataSourceInformationTable == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.DataSourceInformation);
            }

            // copy the table filtering out any rows that don't apply to the current version of the provider
            dataSourceInformationTable = CloneAndFilterCollection(DbMetaDataCollectionNames.DataSourceInformation, null);

            // after filtering there better be just one row
            if (dataSourceInformationTable.Rows.Count != 1){
                throw ADP.IncorrectNumberOfDataSourceInformationRows();
            }
            DataRow dataSourceInformation = dataSourceInformationTable.Rows[0];

            string stringValue;
            Int16 int16Value;
            Int32 int32Value;
            ODBC32.RetCode retcode;

            // update the catalog separator
            stringValue = connection.GetInfoStringUnhandled(ODBC32.SQL_INFO.CATALOG_NAME_SEPARATOR);
            if (!ADP.IsEmpty(stringValue)) {
                StringBuilder patternEscaped = new StringBuilder();
                ADP.EscapeSpecialCharacters(stringValue,patternEscaped);
                dataSourceInformation[DbMetaDataColumnNames.CompositeIdentifierSeparatorPattern] = patternEscaped.ToString();
            }

            // get the DBMS Name
            stringValue = connection.GetInfoStringUnhandled(ODBC32.SQL_INFO.DBMS_NAME);
            if (stringValue != null) {
                dataSourceInformation[DbMetaDataColumnNames.DataSourceProductName] = stringValue;
            }


            // update the server version strings
            dataSourceInformation[DbMetaDataColumnNames.DataSourceProductVersion] = ServerVersion;
            dataSourceInformation[DbMetaDataColumnNames.DataSourceProductVersionNormalized] = ServerVersionNormalized;

            
            // values that are the same for all ODBC drivers. See bug 105333
            dataSourceInformation[DbMetaDataColumnNames.ParameterMarkerFormat] =  "?";
            dataSourceInformation[DbMetaDataColumnNames.ParameterMarkerPattern] =  "\\?";
            dataSourceInformation[DbMetaDataColumnNames.ParameterNameMaxLength] = 0;

            // determine the supportedJoinOperators
            // leave the column null if the GetInfo fails. There is no explicit value for
            // unknown.
            if (connection.IsV3Driver) {
                    
                retcode = connection.GetInfoInt32Unhandled(ODBC32.SQL_INFO.SQL_OJ_CAPABILITIES_30,out int32Value);
            }
            else {
                retcode = connection.GetInfoInt32Unhandled(ODBC32.SQL_INFO.SQL_OJ_CAPABILITIES_20, out int32Value);
            }
                 
            if ((retcode == ODBC32.RetCode.SUCCESS) || (retcode == ODBC32.RetCode.SUCCESS_WITH_INFO)){

                Common. SupportedJoinOperators supportedJoinOperators = Common.SupportedJoinOperators.None;
                if ((int32Value & (Int32)ODBC32.SQL_OJ_CAPABILITIES.LEFT) != 0){
                    supportedJoinOperators = supportedJoinOperators | Common.SupportedJoinOperators.LeftOuter;
                }
                if ((int32Value & (Int32)ODBC32.SQL_OJ_CAPABILITIES.RIGHT) != 0){
                    supportedJoinOperators = supportedJoinOperators | Common.SupportedJoinOperators.RightOuter;
                } 
                if ((int32Value & (Int32)ODBC32.SQL_OJ_CAPABILITIES.FULL) != 0){
                    supportedJoinOperators = supportedJoinOperators | Common.SupportedJoinOperators.FullOuter;
                }
                if ((int32Value & (Int32)ODBC32.SQL_OJ_CAPABILITIES.INNER) != 0){
                    supportedJoinOperators = supportedJoinOperators | Common.SupportedJoinOperators.Inner;
                }
                        
                dataSourceInformation[DbMetaDataColumnNames.SupportedJoinOperators] = supportedJoinOperators;
            }

            // determine the GroupByBehavior
            retcode = connection.GetInfoInt16Unhandled(ODBC32.SQL_INFO.GROUP_BY, out int16Value);
            Common.GroupByBehavior groupByBehavior = Common.GroupByBehavior.Unknown;

            if ((retcode == ODBC32.RetCode.SUCCESS) || (retcode == ODBC32.RetCode.SUCCESS_WITH_INFO)){

                switch (int16Value) {

                    case (Int16)ODBC32.SQL_GROUP_BY.NOT_SUPPORTED:
                        groupByBehavior = Common.GroupByBehavior.NotSupported;
                        break;

                    case (Int16)ODBC32.SQL_GROUP_BY.GROUP_BY_EQUALS_SELECT:
                        groupByBehavior = Common.GroupByBehavior.ExactMatch;
                        break;

                    case (Int16)ODBC32.SQL_GROUP_BY.GROUP_BY_CONTAINS_SELECT:
                        groupByBehavior = Common.GroupByBehavior.MustContainAll;
                        break;

                    case (Int16)ODBC32.SQL_GROUP_BY.NO_RELATION:
                        groupByBehavior = Common.GroupByBehavior.Unrelated;
                        break;
/* COLLATE is new in ODBC 3.0 and GroupByBehavior does not have a value for it.
                    case ODBC32.SQL_GROUP_BY.COLLATE:
                        groupByBehavior = Common.GroupByBehavior.Unknown;
                        break;
*/
                }
            }

            dataSourceInformation[DbMetaDataColumnNames.GroupByBehavior] = groupByBehavior;

            // determine the identifier case
            retcode = connection.GetInfoInt16Unhandled(ODBC32.SQL_INFO.IDENTIFIER_CASE, out int16Value);
            Common.IdentifierCase identifierCase = Common.IdentifierCase.Unknown;

            if ((retcode == ODBC32.RetCode.SUCCESS) || (retcode == ODBC32.RetCode.SUCCESS_WITH_INFO)){

                switch (int16Value) {

                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.SENSITIVE:
                        identifierCase = Common.IdentifierCase.Sensitive;
                        break;

                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.UPPER:
                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.LOWER:
                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.MIXED:
                        identifierCase = Common.IdentifierCase.Insensitive;
                        break;

                }
            }
            dataSourceInformation[DbMetaDataColumnNames.IdentifierCase] = identifierCase;

            // OrderByColumnsInSelect
            stringValue = connection.GetInfoStringUnhandled(ODBC32.SQL_INFO.ORDER_BY_COLUMNS_IN_SELECT);
            if (stringValue != null) {
                if (stringValue == "Y"){
                    dataSourceInformation[DbMetaDataColumnNames.OrderByColumnsInSelect] = true;
                }
                else if (stringValue == "N") {
                    dataSourceInformation[DbMetaDataColumnNames.OrderByColumnsInSelect] = false;
                }
            }

            // build the QuotedIdentifierPattern using the quote prefix and suffix from the provider and
            // assuming that the quote suffix is escaped via repetion (i.e " becomes "")
            stringValue = connection.QuoteChar(ADP.GetSchema);

            if (stringValue != null){

                // by spec a blank identifier quote char indicates that the provider does not suppport
                // quoted identifiers
                if (stringValue != " ") {

                    // only know how to build the parttern if the quote characters is 1 character
                    // in all other cases just leave the field null
                    if (stringValue.Length == 1) {
                        StringBuilder scratchStringBuilder = new StringBuilder();
                        ADP.EscapeSpecialCharacters(stringValue,scratchStringBuilder );
                        string escapedQuoteSuffixString = scratchStringBuilder.ToString();
                        scratchStringBuilder.Length = 0;

                        ADP.EscapeSpecialCharacters(stringValue, scratchStringBuilder);
                        scratchStringBuilder.Append("(([^");
                        scratchStringBuilder.Append(escapedQuoteSuffixString);
                        scratchStringBuilder.Append("]|");
                        scratchStringBuilder.Append(escapedQuoteSuffixString);
                        scratchStringBuilder.Append(escapedQuoteSuffixString);
                        scratchStringBuilder.Append(")*)");
                        scratchStringBuilder.Append(escapedQuoteSuffixString);
                        dataSourceInformation[DbMetaDataColumnNames.QuotedIdentifierPattern] = scratchStringBuilder.ToString();
                    }
                }
            }

            // determine the quoted identifier case
            retcode = connection.GetInfoInt16Unhandled(ODBC32.SQL_INFO.QUOTED_IDENTIFIER_CASE, out int16Value);
            Common.IdentifierCase quotedIdentifierCase = Common.IdentifierCase.Unknown;

            if ((retcode == ODBC32.RetCode.SUCCESS) || (retcode == ODBC32.RetCode.SUCCESS_WITH_INFO)){

                switch (int16Value) {

                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.SENSITIVE:
                        quotedIdentifierCase = Common.IdentifierCase.Sensitive;
                        break;

                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.UPPER:
                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.LOWER:
                    case (Int16)ODBC32.SQL_IDENTIFIER_CASE.MIXED:
                        quotedIdentifierCase = Common.IdentifierCase.Insensitive;
                        break;

                }
            }
            dataSourceInformation[DbMetaDataColumnNames.QuotedIdentifierCase] = quotedIdentifierCase;

            dataSourceInformationTable.AcceptChanges();

            return dataSourceInformationTable;
        }


        private DataTable GetDataTypesCollection(String[] restrictions, OdbcConnection connection){
            
            if (ADP.IsEmptyArray(restrictions) == false){
                throw ADP.TooManyRestrictions(DbMetaDataCollectionNames.DataTypes);
            }

            

            // verify the existence of the table in the data set
            DataTable dataTypesTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.DataTypes];
            if (dataTypesTable == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.DataTypes);
            }

            // copy the data table it
            dataTypesTable = CloneAndFilterCollection(DbMetaDataCollectionNames.DataTypes, null);

            OdbcCommand command = null;
            OdbcDataReader dataReader =null;
            object[] allArguments = new object[1];
            allArguments[0] = ODBC32.SQL_ALL_TYPES;

            try {
                command = GetCommand(connection);


                dataReader = command.ExecuteReaderFromSQLMethod(allArguments, ODBC32.SQL_API.SQLGETTYPEINFO);

                DataTableFromDataReaderDataTypes(dataTypesTable,dataReader,connection);
            }

            finally {
                if (dataReader != null) {
                    dataReader.Dispose();
                };
                if (command != null) {
                    command.Dispose();
                };
            }
            dataTypesTable.AcceptChanges();
            return  dataTypesTable;
        }

        private DataTable GetIndexCollection(String[] restrictions, OdbcConnection connection){

            OdbcCommand command = null;
            OdbcDataReader dataReader =null;
            DataTable resultTable = null;
            const int nativeRestrictionsCount = 5;
            const int indexRestrictionsCount = 4;
            const int indexOfTableName = 2;
            const int indexOfIndexName = 3;
            
            try {
                command = GetCommand(connection);
                object[] allRestrictions = new object[nativeRestrictionsCount];
                FillOutRestrictions(indexRestrictionsCount,restrictions,allRestrictions,OdbcMetaDataCollectionNames.Indexes);

                if (allRestrictions[indexOfTableName] == null) {
                    throw ODBC.GetSchemaRestrictionRequired();
                }

                allRestrictions[3] = (Int16)ODBC32.SQL_INDEX.ALL;
                allRestrictions[4] = (Int16)ODBC32.SQL_STATISTICS_RESERVED.ENSURE;

                dataReader = command.ExecuteReaderFromSQLMethod(allRestrictions, ODBC32.SQL_API.SQLSTATISTICS);

                string indexName = null;
                if (restrictions != null) {

                    if (restrictions.Length >= indexOfIndexName+1) {
                       indexName = restrictions[indexOfIndexName];
                    }
                }

                resultTable = DataTableFromDataReaderIndex(dataReader,
                                                           OdbcMetaDataCollectionNames.Indexes,
                                                           indexName);
            }

            finally {
                if (dataReader != null) {
                    dataReader.Dispose();
                };
                if (command != null) {
                    command.Dispose();
                };
            }
            return resultTable;
        }

        private DataTable GetProcedureColumnsCollection(String[] restrictions, OdbcConnection connection,Boolean isColumns){

            OdbcCommand command = null;
            OdbcDataReader dataReader =null;
            DataTable resultTable = null;
            const int  procedureColumnsRestrictionsCount = 4;

            try {
                command = GetCommand(connection);
                String[] allRestrictions = new string[procedureColumnsRestrictionsCount];
                FillOutRestrictions(procedureColumnsRestrictionsCount,restrictions, allRestrictions,OdbcMetaDataCollectionNames.Columns);

                dataReader = command.ExecuteReaderFromSQLMethod(allRestrictions,ODBC32.SQL_API.SQLPROCEDURECOLUMNS);

                string collectionName;
                if (isColumns == true) {
                   collectionName = OdbcMetaDataCollectionNames.ProcedureColumns;
                }
                else {
                    collectionName = OdbcMetaDataCollectionNames.ProcedureParameters;
                }
                resultTable = DataTableFromDataReaderProcedureColumns(dataReader,
                                                                      collectionName,
                                                                      isColumns);
            }

            finally {
                if (dataReader != null) {
                    dataReader.Dispose();
                };
                if (command != null) {
                    command.Dispose();
                };
            }
            return resultTable;
        }

        private DataTable GetProceduresCollection(String[] restrictions, OdbcConnection connection){

            OdbcCommand command = null;
            OdbcDataReader dataReader =null;
            DataTable resultTable = null;
            const int  columnsRestrictionsCount = 4;
            const int indexOfProcedureType = 3;

            try {
                command = GetCommand(connection);
                String[] allRestrictions = new string[columnsRestrictionsCount];
                FillOutRestrictions(columnsRestrictionsCount,restrictions, allRestrictions,OdbcMetaDataCollectionNames.Procedures);


                dataReader = command.ExecuteReaderFromSQLMethod(allRestrictions,ODBC32.SQL_API.SQLPROCEDURES);

                if (allRestrictions[indexOfProcedureType] == null) {
                    resultTable = DataTableFromDataReader(dataReader, OdbcMetaDataCollectionNames.Procedures);
                }
                else {
                    Int16 procedureType;
                    if ((restrictions[indexOfProcedureType] == "SQL_PT_UNKNOWN") ||
                            (restrictions[indexOfProcedureType] == "0" /*ODBC32.SQL_PROCEDURETYPE.UNKNOWN*/)) {
                            procedureType = (Int16)ODBC32.SQL_PROCEDURETYPE.UNKNOWN;
                        }
                    else if ((restrictions[indexOfProcedureType] == "SQL_PT_PROCEDURE") ||
                             (restrictions[indexOfProcedureType] == "1" /*ODBC32.SQL_PROCEDURETYPE.PROCEDURE*/)) {
                        procedureType = (Int16)ODBC32.SQL_PROCEDURETYPE.PROCEDURE;
                    }
                    else if ((restrictions[indexOfProcedureType] == "SQL_PT_FUNCTION") ||
                             (restrictions[indexOfProcedureType] == "2" /*ODBC32.SQL_PROCEDURETYPE.FUNCTION*/)) {
                        procedureType = (Int16)ODBC32.SQL_PROCEDURETYPE.FUNCTION;
                    }
                    else{
                        throw ADP.InvalidRestrictionValue(OdbcMetaDataCollectionNames.Procedures,"PROCEDURE_TYPE",restrictions[indexOfProcedureType]);
                    }

                    resultTable = DataTableFromDataReaderProcedures(dataReader, OdbcMetaDataCollectionNames.Procedures,procedureType);

                }

            }

            finally {
                if (dataReader != null) {
                    dataReader.Dispose();
                };
                if (command != null) {
                    command.Dispose();
                };
            }
            return resultTable;
        }

        private DataTable GetReservedWordsCollection(string[] restrictions, OdbcConnection connection){

            if (ADP.IsEmptyArray(restrictions) == false){
               throw ADP.TooManyRestrictions(DbMetaDataCollectionNames.ReservedWords);
            }

            // verify the existence of the table in the data set
            DataTable reservedWordsTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.ReservedWords];
            if (reservedWordsTable == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.ReservedWords);
            }

            // copy the table filtering out any rows that don't apply to tho current version of the provider
            reservedWordsTable = CloneAndFilterCollection(DbMetaDataCollectionNames.ReservedWords, null);

            DataColumn reservedWordColumn = reservedWordsTable.Columns[DbMetaDataColumnNames.ReservedWord];
            if (reservedWordColumn == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.ReservedWords);
            }

            string keywords = connection.GetInfoStringUnhandled(ODBC32.SQL_INFO.KEYWORDS);

            if (null != keywords) {
                string[] values = keywords.Split(KeywordSeparatorChar);
                for (int i = 0; i < values.Length; ++i) {
                    DataRow row = reservedWordsTable.NewRow();
                    row[reservedWordColumn] = values[i];

                    reservedWordsTable.Rows.Add(row);
                    row.AcceptChanges();
                }
            }

            return  reservedWordsTable;
        }

        private DataTable GetTablesCollection(String[] restrictions, OdbcConnection connection, Boolean isTables){

            OdbcCommand command = null;
            OdbcDataReader dataReader =null;
            DataTable resultTable = null;
            const int  tablesRestrictionsCount = 3;
            const string includedTableTypesTables =  "TABLE,SYSTEM TABLE";
            const string includedTableTypesViews = "VIEW";
            string includedTableTypes;
            string dataTableName;

            try {
                //command = (OdbcCommand) connection.CreateCommand();
                command = GetCommand(connection);
                string [] allArguments = new string[tablesRestrictionsCount+1];
                if (isTables == true) {
                    includedTableTypes = includedTableTypesTables;
                    dataTableName = OdbcMetaDataCollectionNames.Tables;
                }
                else {
                    includedTableTypes = includedTableTypesViews;
                    dataTableName = OdbcMetaDataCollectionNames.Views;
                }
                FillOutRestrictions(tablesRestrictionsCount,restrictions,allArguments,dataTableName);

                allArguments[tablesRestrictionsCount] = includedTableTypes;

                dataReader = command.ExecuteReaderFromSQLMethod(allArguments, ODBC32.SQL_API.SQLTABLES);

                resultTable = DataTableFromDataReader(dataReader,dataTableName);
            }

            finally {
                if (dataReader != null) {
                    dataReader.Dispose();
                };
                if (command != null) {
                    command.Dispose();
                };
            }
            return resultTable;
        }

        private Boolean IncludeIndexRow(object rowIndexName,
                                        string restrictionIndexName,
                                        Int16 rowIndexType) {
            // never include table statictics rows
            if (rowIndexType == (Int16)ODBC32.SQL_STATISTICSTYPE.TABLE_STAT) {
                return false;
            }

            if ((restrictionIndexName != null) && (restrictionIndexName != (string)rowIndexName)) {
                return false;
            }

           return true;
        }

        private DataTable NewDataTableFromReader(IDataReader reader, out object[] values, string tableName){

            DataTable resultTable = new DataTable(tableName);
            resultTable.Locale = System.Globalization.CultureInfo.InvariantCulture;
            DataTable schemaTable = reader.GetSchemaTable();
            foreach (DataRow row in schemaTable.Rows){
                resultTable.Columns.Add(row["ColumnName"] as string, (Type)row["DataType"] as Type);
            }

            values = new object[resultTable.Columns.Count];
            return resultTable;
        }

        protected override DataTable PrepareCollection(String collectionName, String[] restrictions, DbConnection connection){

            DataTable resultTable = null;
            OdbcConnection odbcConnection = (OdbcConnection) connection;

            if (collectionName == OdbcMetaDataCollectionNames.Tables) {
                resultTable = GetTablesCollection(restrictions, odbcConnection, true);
            }
            else if (collectionName == OdbcMetaDataCollectionNames.Views) {
                resultTable = GetTablesCollection(restrictions, odbcConnection, false);
            }
            else if (collectionName == OdbcMetaDataCollectionNames.Columns) {
                resultTable = GetColumnsCollection(restrictions, odbcConnection);
            }
            else if (collectionName == OdbcMetaDataCollectionNames.Procedures) {
                resultTable = GetProceduresCollection(restrictions, odbcConnection);
            }
            else if (collectionName == OdbcMetaDataCollectionNames.ProcedureColumns) {
                resultTable = GetProcedureColumnsCollection(restrictions, odbcConnection, true);
            }
            else if (collectionName == OdbcMetaDataCollectionNames.ProcedureParameters) {
                resultTable = GetProcedureColumnsCollection(restrictions, odbcConnection, false);
            }
            else if (collectionName == OdbcMetaDataCollectionNames.Indexes) {
                resultTable = GetIndexCollection(restrictions, odbcConnection);
            }
            else if (collectionName == DbMetaDataCollectionNames.DataTypes) {
                resultTable = GetDataTypesCollection(restrictions, odbcConnection);
            }
            else if (collectionName == DbMetaDataCollectionNames.DataSourceInformation) {
                resultTable = GetDataSourceInformationCollection(restrictions, odbcConnection);
            }
            else if (collectionName == DbMetaDataCollectionNames.ReservedWords) {
                resultTable = GetReservedWordsCollection(restrictions, odbcConnection);
            }

            if (resultTable == null){
               throw ADP.UnableToBuildCollection(collectionName);
            }

            return resultTable;
        }



   }
}