1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618
|
//------------------------------------------------------------------------------
// <copyright file="EntityCommandDefinition.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//
// @owner Microsoft
// @backupOwner Microsoft
//------------------------------------------------------------------------------
namespace System.Data.EntityClient {
using System.Collections.Generic;
using System.Data.Common;
using System.Data.Common.CommandTrees;
using System.Data.Common.Utils;
using System.Data.Mapping;
using System.Data.Metadata.Edm;
using System.Data.Query.InternalTrees;
using System.Data.Query.PlanCompiler;
using System.Data.Query.ResultAssembly;
using System.Diagnostics;
using System.Linq;
using System.Text;
/// <summary>
/// An aggregate Command Definition used by the EntityClient layers. This is an aggregator
/// object that represent information from multiple underlying provider commands.
/// </summary>
sealed internal class EntityCommandDefinition : DbCommandDefinition {
#region internal state
/// <summary>
/// nested store command definitions
/// </summary>
private readonly List<DbCommandDefinition> _mappedCommandDefinitions;
/// <summary>
/// generates column map for the store result reader
/// </summary>
private readonly IColumnMapGenerator[] _columnMapGenerators;
/// <summary>
/// list of the parameters that the resulting command should have
/// </summary>
private readonly System.Collections.ObjectModel.ReadOnlyCollection<EntityParameter> _parameters;
/// <summary>
/// Set of entity sets exposed in the command.
/// </summary>
private readonly Set<EntitySet> _entitySets;
#endregion
#region constructors
/// <summary>
/// don't let this be constructed publicly;
/// </summary>
/// <exception cref="EntityCommandCompilationException">Cannot prepare the command definition for execution; consult the InnerException for more information.</exception>
/// <exception cref="NotSupportedException">The ADO.NET Data Provider you are using does not support CommandTrees.</exception>
internal EntityCommandDefinition(DbProviderFactory storeProviderFactory, DbCommandTree commandTree) {
EntityUtil.CheckArgumentNull(storeProviderFactory, "storeProviderFactory");
EntityUtil.CheckArgumentNull(commandTree, "commandTree");
DbProviderServices storeProviderServices = DbProviderServices.GetProviderServices(storeProviderFactory);
try {
if (DbCommandTreeKind.Query == commandTree.CommandTreeKind) {
// Next compile the plan for the command tree
List<ProviderCommandInfo> mappedCommandList = new List<ProviderCommandInfo>();
ColumnMap columnMap;
int columnCount;
PlanCompiler.Compile(commandTree, out mappedCommandList, out columnMap, out columnCount, out _entitySets);
_columnMapGenerators = new IColumnMapGenerator[] {new ConstantColumnMapGenerator(columnMap, columnCount)};
// Note: we presume that the first item in the ProviderCommandInfo is the root node;
Debug.Assert(mappedCommandList.Count > 0, "empty providerCommandInfo collection and no exception?"); // this shouldn't ever happen.
// Then, generate the store commands from the resulting command tree(s)
_mappedCommandDefinitions = new List<DbCommandDefinition>(mappedCommandList.Count);
foreach (ProviderCommandInfo providerCommandInfo in mappedCommandList) {
DbCommandDefinition providerCommandDefinition = storeProviderServices.CreateCommandDefinition(providerCommandInfo.CommandTree);
if (null == providerCommandDefinition) {
throw EntityUtil.ProviderIncompatible(System.Data.Entity.Strings.ProviderReturnedNullForCreateCommandDefinition);
}
_mappedCommandDefinitions.Add(providerCommandDefinition);
}
}
else {
Debug.Assert(DbCommandTreeKind.Function == commandTree.CommandTreeKind, "only query and function command trees are supported");
DbFunctionCommandTree entityCommandTree = (DbFunctionCommandTree)commandTree;
// Retrieve mapping and metadata information for the function import.
FunctionImportMappingNonComposable mapping = GetTargetFunctionMapping(entityCommandTree);
IList<FunctionParameter> returnParameters = entityCommandTree.EdmFunction.ReturnParameters;
int resultSetCount = returnParameters.Count > 1 ? returnParameters.Count : 1;
_columnMapGenerators = new IColumnMapGenerator[resultSetCount];
TypeUsage storeResultType = DetermineStoreResultType(entityCommandTree.MetadataWorkspace, mapping, 0, out _columnMapGenerators[0]);
for (int i = 1; i < resultSetCount; i++)
{
DetermineStoreResultType(entityCommandTree.MetadataWorkspace, mapping, i, out _columnMapGenerators[i]);
}
// Copy over parameters (this happens through a more indirect route in the plan compiler, but
// it happens nonetheless)
List<KeyValuePair<string, TypeUsage>> providerParameters = new List<KeyValuePair<string, TypeUsage>>();
foreach (KeyValuePair<string, TypeUsage> parameter in entityCommandTree.Parameters)
{
providerParameters.Add(parameter);
}
// Construct store command tree usage.
DbFunctionCommandTree providerCommandTree = new DbFunctionCommandTree(entityCommandTree.MetadataWorkspace, DataSpace.SSpace,
mapping.TargetFunction, storeResultType, providerParameters);
DbCommandDefinition storeCommandDefinition = storeProviderServices.CreateCommandDefinition(providerCommandTree);
_mappedCommandDefinitions = new List<DbCommandDefinition>(1) { storeCommandDefinition };
EntitySet firstResultEntitySet = mapping.FunctionImport.EntitySets.FirstOrDefault();
if (firstResultEntitySet != null)
{
_entitySets = new Set<EntitySet>();
_entitySets.Add(mapping.FunctionImport.EntitySets.FirstOrDefault());
_entitySets.MakeReadOnly();
}
}
// Finally, build a list of the parameters that the resulting command should have;
List<EntityParameter> parameterList = new List<EntityParameter>();
foreach (KeyValuePair<string, TypeUsage> queryParameter in commandTree.Parameters) {
EntityParameter parameter = CreateEntityParameterFromQueryParameter(queryParameter);
parameterList.Add(parameter);
}
_parameters = new System.Collections.ObjectModel.ReadOnlyCollection<EntityParameter>(parameterList);
}
catch (EntityCommandCompilationException) {
// No need to re-wrap EntityCommandCompilationException
throw;
}
catch (Exception e) {
// we should not be wrapping all exceptions
if (EntityUtil.IsCatchableExceptionType(e)) {
// we don't wan't folks to have to know all the various types of exceptions that can
// occur, so we just rethrow a CommandDefinitionException and make whatever we caught
// the inner exception of it.
throw EntityUtil.CommandCompilation(System.Data.Entity.Strings.EntityClient_CommandDefinitionPreparationFailed, e);
}
throw;
}
}
/// <summary>
/// Determines the store type for a function import.
/// </summary>
private TypeUsage DetermineStoreResultType(MetadataWorkspace workspace, FunctionImportMappingNonComposable mapping, int resultSetIndex, out IColumnMapGenerator columnMapGenerator) {
// Determine column maps and infer result types for the mapped function. There are four varieties:
// Collection(Entity)
// Collection(PrimitiveType)
// Collection(ComplexType)
// No result type
TypeUsage storeResultType;
{
StructuralType baseStructuralType;
EdmFunction functionImport = mapping.FunctionImport;
// Collection(Entity) or Collection(ComplexType)
if (MetadataHelper.TryGetFunctionImportReturnType<StructuralType>(functionImport, resultSetIndex, out baseStructuralType))
{
ValidateEdmResultType(baseStructuralType, functionImport);
//Note: Defensive check for historic reasons, we expect functionImport.EntitySets.Count > resultSetIndex
EntitySet entitySet = functionImport.EntitySets.Count > resultSetIndex ? functionImport.EntitySets[resultSetIndex] : null;
columnMapGenerator = new FunctionColumnMapGenerator(mapping, resultSetIndex, entitySet, baseStructuralType);
// We don't actually know the return type for the stored procedure, but we can infer
// one based on the mapping (i.e.: a column for every property of the mapped types
// and for all discriminator columns)
storeResultType = mapping.GetExpectedTargetResultType(workspace, resultSetIndex);
}
// Collection(PrimitiveType)
else
{
FunctionParameter returnParameter = MetadataHelper.GetReturnParameter(functionImport, resultSetIndex);
if (returnParameter != null && returnParameter.TypeUsage != null)
{
// Get metadata description of the return type
storeResultType = returnParameter.TypeUsage;
Debug.Assert(storeResultType.EdmType.BuiltInTypeKind == BuiltInTypeKind.CollectionType, "FunctionImport currently supports only collection result type");
TypeUsage elementType = ((CollectionType)storeResultType.EdmType).TypeUsage;
Debug.Assert(Helper.IsScalarType(elementType.EdmType)
, "FunctionImport supports only Collection(Entity), Collection(Enum) and Collection(Primitive)");
// Build collection column map where the first column of the store result is assumed
// to contain the primitive type values.
ScalarColumnMap scalarColumnMap = new ScalarColumnMap(elementType, string.Empty, 0, 0);
SimpleCollectionColumnMap collectionColumnMap = new SimpleCollectionColumnMap(storeResultType,
string.Empty, scalarColumnMap, null, null);
columnMapGenerator = new ConstantColumnMapGenerator(collectionColumnMap, 1);
}
// No result type
else
{
storeResultType = null;
columnMapGenerator = new ConstantColumnMapGenerator(null, 0);
}
}
}
return storeResultType;
}
/// <summary>
/// Handles the following negative scenarios
/// Nested ComplexType Property in ComplexType
/// </summary>
/// <param name="resultType"></param>
private void ValidateEdmResultType(EdmType resultType, EdmFunction functionImport)
{
if (Helper.IsComplexType(resultType))
{
ComplexType complexType = resultType as ComplexType;
Debug.Assert(null != complexType, "we should have a complex type here");
foreach (var property in complexType.Properties)
{
if (property.TypeUsage.EdmType.BuiltInTypeKind == BuiltInTypeKind.ComplexType)
{
throw new NotSupportedException(System.Data.Entity.Strings.ComplexTypeAsReturnTypeAndNestedComplexProperty(property.Name, complexType.Name, functionImport.FullName));
}
}
}
}
/// <summary>
/// Retrieves mapping for the given C-Space functionCommandTree
/// </summary>
private static FunctionImportMappingNonComposable GetTargetFunctionMapping(DbFunctionCommandTree functionCommandTree)
{
Debug.Assert(functionCommandTree.DataSpace == DataSpace.CSpace, "map from CSpace->SSpace function");
Debug.Assert(functionCommandTree != null, "null functionCommandTree");
Debug.Assert(!functionCommandTree.EdmFunction.IsComposableAttribute, "functionCommandTree.EdmFunction must be non-composable.");
// Find mapped store function.
FunctionImportMapping targetFunctionMapping;
if (!functionCommandTree.MetadataWorkspace.TryGetFunctionImportMapping(functionCommandTree.EdmFunction, out targetFunctionMapping))
{
throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.EntityClient_UnmappedFunctionImport(functionCommandTree.EdmFunction.FullName));
}
return (FunctionImportMappingNonComposable)targetFunctionMapping;
}
#endregion
#region public API
/// <summary>
/// Create a DbCommand object from the definition, that can be executed
/// </summary>
/// <returns></returns>
public override DbCommand CreateCommand() {
return new EntityCommand(this);
}
#endregion
#region internal methods
/// <summary>
/// Get a list of commands to be executed by the provider
/// </summary>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
internal IEnumerable<string> MappedCommands {
get {
// Build up the list of command texts, if we haven't done so yet
List<string> mappedCommandTexts = new List<string>();
foreach (DbCommandDefinition commandDefinition in _mappedCommandDefinitions) {
DbCommand mappedCommand = commandDefinition.CreateCommand();
mappedCommandTexts.Add(mappedCommand.CommandText);
}
return mappedCommandTexts;
}
}
/// <summary>
/// Creates ColumnMap for result assembly using the given reader.
/// </summary>
internal ColumnMap CreateColumnMap(DbDataReader storeDataReader)
{
return CreateColumnMap(storeDataReader, 0);
}
/// <summary>
/// Creates ColumnMap for result assembly using the given reader's resultSetIndexth result set.
/// </summary>
internal ColumnMap CreateColumnMap(DbDataReader storeDataReader, int resultSetIndex)
{
return _columnMapGenerators[resultSetIndex].CreateColumnMap(storeDataReader);
}
/// <summary>
/// Property to expose the known parameters for the query, so the Command objects
/// constructor can poplulate it's parameter collection from.
/// </summary>
internal IEnumerable<EntityParameter> Parameters {
get {
return _parameters;
}
}
/// <summary>
/// Set of entity sets exposed in the command.
/// </summary>
internal Set<EntitySet> EntitySets {
get {
return _entitySets;
}
}
/// <summary>
/// Constructs a EntityParameter from a CQT parameter.
/// </summary>
/// <param name="queryParameter"></param>
/// <returns></returns>
private static EntityParameter CreateEntityParameterFromQueryParameter(KeyValuePair<string, TypeUsage> queryParameter) {
// We really can't have a parameter here that isn't a scalar type...
Debug.Assert(TypeSemantics.IsScalarType(queryParameter.Value), "Non-scalar type used as query parameter type");
EntityParameter result = new EntityParameter();
result.ParameterName = queryParameter.Key;
EntityCommandDefinition.PopulateParameterFromTypeUsage(result, queryParameter.Value, isOutParam: false);
return result;
}
internal static void PopulateParameterFromTypeUsage(EntityParameter parameter, TypeUsage type, bool isOutParam)
{
// type can be null here if the type provided by the user is not a known model type
if (type != null)
{
PrimitiveTypeKind primitiveTypeKind;
if (Helper.IsEnumType(type.EdmType))
{
type = TypeUsage.Create(Helper.GetUnderlyingEdmTypeForEnumType(type.EdmType));
}
else if (Helper.IsSpatialType(type, out primitiveTypeKind))
{
parameter.EdmType = EdmProviderManifest.Instance.GetPrimitiveType(primitiveTypeKind);
}
}
DbCommandDefinition.PopulateParameterFromTypeUsage(parameter, type, isOutParam);
}
/// <summary>
/// Internal execute method -- copies command information from the map command
/// to the command objects, executes them, and builds the result assembly
/// structures needed to return the data reader
/// </summary>
/// <param name="entityCommand"></param>
/// <param name="behavior"></param>
/// <returns></returns>
/// <exception cref="InvalidOperationException">behavior must specify CommandBehavior.SequentialAccess</exception>
/// <exception cref="InvalidOperationException">input parameters in the entityCommand.Parameters collection must have non-null values.</exception>
internal DbDataReader Execute(EntityCommand entityCommand, CommandBehavior behavior) {
if (CommandBehavior.SequentialAccess != (behavior & CommandBehavior.SequentialAccess)) {
throw EntityUtil.MustUseSequentialAccess();
}
DbDataReader storeDataReader = ExecuteStoreCommands(entityCommand, behavior);
DbDataReader result = null;
// If we actually executed something, then go ahead and construct a bridge
// data reader for it.
if (null != storeDataReader) {
try {
ColumnMap columnMap = this.CreateColumnMap(storeDataReader, 0);
if (null == columnMap) {
// For a query with no result type (and therefore no column map), consume the reader.
// When the user requests Metadata for this reader, we return nothing.
CommandHelper.ConsumeReader(storeDataReader);
result = storeDataReader;
}
else {
result = BridgeDataReader.Create(storeDataReader, columnMap, entityCommand.Connection.GetMetadataWorkspace(), GetNextResultColumnMaps(storeDataReader));
}
}
catch {
// dispose of store reader if there is an error creating the BridgeDataReader
storeDataReader.Dispose();
throw;
}
}
return result;
}
private IEnumerable<ColumnMap> GetNextResultColumnMaps(DbDataReader storeDataReader)
{
for (int i = 1; i < _columnMapGenerators.Length; ++i)
{
yield return this.CreateColumnMap(storeDataReader, i);
}
}
/// <summary>
/// Execute the store commands, and return IteratorSources for each one
/// </summary>
/// <param name="entityCommand"></param>
/// <param name="behavior"></param>
internal DbDataReader ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)
{
// SQLPT #120007433 is the work item to implement MARS support, which we
// need to do here, but since the PlanCompiler doesn't
// have it yet, neither do we...
if (1 != _mappedCommandDefinitions.Count) {
throw EntityUtil.NotSupported("MARS");
}
EntityTransaction entityTransaction = CommandHelper.GetEntityTransaction(entityCommand);
DbCommandDefinition definition = _mappedCommandDefinitions[0];
DbCommand storeProviderCommand = definition.CreateCommand();
CommandHelper.SetStoreProviderCommandState(entityCommand, entityTransaction, storeProviderCommand);
// Copy over the values from the map command to the store command; we
// assume that they were not renamed by either the plan compiler or SQL
// Generation.
//
// Note that this pretty much presumes that named parameters are supported
// by the store provider, but it might work if we don't reorder/reuse
// parameters.
//
// Note also that the store provider may choose to add parameters to thier
// command object for some things; we'll only copy over the values for
// parameters that we find in the EntityCommands parameters collection, so
// we won't damage anything the store provider did.
bool hasOutputParameters = false;
if (storeProviderCommand.Parameters != null) // SQLBUDT 519066
{
DbProviderServices storeProviderServices = DbProviderServices.GetProviderServices(entityCommand.Connection.StoreProviderFactory);
foreach (DbParameter storeParameter in storeProviderCommand.Parameters) {
// I could just use the string indexer, but then if I didn't find it the
// consumer would get some ParameterNotFound exeception message and that
// wouldn't be very meaningful. Instead, I use the IndexOf method and
// if I don't find it, it's not a big deal (The store provider must
// have added it).
int parameterOrdinal = entityCommand.Parameters.IndexOf(storeParameter.ParameterName);
if (-1 != parameterOrdinal) {
EntityParameter entityParameter = entityCommand.Parameters[parameterOrdinal];
SyncParameterProperties(entityParameter, storeParameter, storeProviderServices);
if (storeParameter.Direction != ParameterDirection.Input) {
hasOutputParameters = true;
}
}
}
}
// If the EntityCommand has output parameters, we must synchronize parameter values when
// the reader is closed. Tell the EntityCommand about the store command so that it knows
// where to pull those values from.
if (hasOutputParameters) {
entityCommand.SetStoreProviderCommand(storeProviderCommand);
}
DbDataReader reader = null;
try {
reader = storeProviderCommand.ExecuteReader(behavior & ~CommandBehavior.SequentialAccess);
}
catch (Exception e) {
// we should not be wrapping all exceptions
if (EntityUtil.IsCatchableExceptionType(e)) {
// we don't wan't folks to have to know all the various types of exceptions that can
// occur, so we just rethrow a CommandDefinitionException and make whatever we caught
// the inner exception of it.
throw EntityUtil.CommandExecution(System.Data.Entity.Strings.EntityClient_CommandDefinitionExecutionFailed, e);
}
throw;
}
return reader;
}
/// <summary>
/// Updates storeParameter size, precision and scale properties from user provided parameter properties.
/// </summary>
/// <param name="entityParameter"></param>
/// <param name="storeParameter"></param>
private static void SyncParameterProperties(EntityParameter entityParameter, DbParameter storeParameter, DbProviderServices storeProviderServices) {
IDbDataParameter dbDataParameter = (IDbDataParameter)storeParameter;
// DBType is not currently syncable; it's part of the cache key anyway; this is because we can't guarantee
// that the store provider will honor it -- (SqlClient doesn't...)
//if (entityParameter.IsDbTypeSpecified)
//{
// storeParameter.DbType = entityParameter.DbType;
//}
// Give the store provider the opportunity to set the value before any parameter state has been copied from
// the EntityParameter.
TypeUsage parameterTypeUsage = TypeHelpers.GetPrimitiveTypeUsageForScalar(entityParameter.GetTypeUsage());
storeProviderServices.SetParameterValue(storeParameter, parameterTypeUsage, entityParameter.Value);
// Override the store provider parameter state with any explicitly specified values from the EntityParameter.
if (entityParameter.IsDirectionSpecified)
{
storeParameter.Direction = entityParameter.Direction;
}
if (entityParameter.IsIsNullableSpecified)
{
storeParameter.IsNullable = entityParameter.IsNullable;
}
if (entityParameter.IsSizeSpecified)
{
storeParameter.Size = entityParameter.Size;
}
if (entityParameter.IsPrecisionSpecified)
{
dbDataParameter.Precision = entityParameter.Precision;
}
if (entityParameter.IsScaleSpecified)
{
dbDataParameter.Scale = entityParameter.Scale;
}
}
/// <summary>
/// Return the string used by EntityCommand and ObjectQuery<T> ToTraceString"/>
/// </summary>
/// <returns></returns>
internal string ToTraceString() {
if (_mappedCommandDefinitions != null) {
if (_mappedCommandDefinitions.Count == 1) {
// Gosh it sure would be nice if I could just get the inner commandText, but
// that would require more public surface area on DbCommandDefinition, or
// me to know about the inner object...
return _mappedCommandDefinitions[0].CreateCommand().CommandText;
}
else {
StringBuilder sb = new StringBuilder();
foreach (DbCommandDefinition commandDefinition in _mappedCommandDefinitions) {
DbCommand mappedCommand = commandDefinition.CreateCommand();
sb.Append(mappedCommand.CommandText);
}
return sb.ToString();
}
}
return string.Empty;
}
#endregion
#region nested types
/// <summary>
/// Generates a column map given a data reader.
/// </summary>
private interface IColumnMapGenerator {
/// <summary>
/// Given a data reader, returns column map.
/// </summary>
/// <param name="reader">Data reader.</param>
/// <returns>Column map.</returns>
ColumnMap CreateColumnMap(DbDataReader reader);
}
/// <summary>
/// IColumnMapGenerator wrapping a constant instance of a column map (invariant with respect
/// to the given DbDataReader)
/// </summary>
private sealed class ConstantColumnMapGenerator : IColumnMapGenerator {
private readonly ColumnMap _columnMap;
private readonly int _fieldsRequired;
internal ConstantColumnMapGenerator(ColumnMap columnMap, int fieldsRequired) {
_columnMap = columnMap;
_fieldsRequired = fieldsRequired;
}
ColumnMap IColumnMapGenerator.CreateColumnMap(DbDataReader reader) {
if (null != reader && reader.FieldCount < _fieldsRequired) {
throw EntityUtil.CommandExecution(System.Data.Entity.Strings.EntityClient_TooFewColumns);
}
return _columnMap;
}
}
/// <summary>
/// Generates column maps for a non-composable function mapping.
/// </summary>
private sealed class FunctionColumnMapGenerator : IColumnMapGenerator {
private readonly FunctionImportMappingNonComposable _mapping;
private readonly EntitySet _entitySet;
private readonly StructuralType _baseStructuralType;
private readonly int _resultSetIndex;
internal FunctionColumnMapGenerator(FunctionImportMappingNonComposable mapping, int resultSetIndex, EntitySet entitySet, StructuralType baseStructuralType)
{
_mapping = mapping;
_entitySet = entitySet;
_baseStructuralType = baseStructuralType;
_resultSetIndex = resultSetIndex;
}
ColumnMap IColumnMapGenerator.CreateColumnMap(DbDataReader reader)
{
return ColumnMapFactory.CreateFunctionImportStructuralTypeColumnMap(reader, _mapping, _resultSetIndex, _entitySet, _baseStructuralType);
}
}
#endregion
}
}
|