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// Copyright (c) 2008 MySQL AB, 2008-2010 Sun Microsystems, Inc.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most
// MySQL Connectors. There are special exceptions to the terms and
// conditions of the GPLv2 as it is applied to this software, see the
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published
// by the Free Software Foundation; version 2 of the License.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Common.CommandTrees;
using System.Diagnostics;
namespace MySql.Data.Entity
{
class FunctionProcessor
{
private static readonly Dictionary<string, string> bitwiseFunctions =
new Dictionary<string, string>();
private static readonly Dictionary<string, string> dateFunctions =
new Dictionary<string, string>();
private static readonly Dictionary<string, string> stringFunctions =
new Dictionary<string, string>();
private static readonly Dictionary<string, string> mathFunctions =
new Dictionary<string, string>();
private SqlGenerator callingGenerator;
static FunctionProcessor()
{
bitwiseFunctions.Add("BitwiseAnd", "&");
bitwiseFunctions.Add("BitwiseNot", "!");
bitwiseFunctions.Add("BitwiseOr", "|");
bitwiseFunctions.Add("BitwiseXor", "^");
dateFunctions.Add("CurrentDateTime", "NOW()");
dateFunctions.Add("Year", "YEAR({0})");
dateFunctions.Add("Month", "MONTH({0})");
dateFunctions.Add("Day", "DAY({0})");
dateFunctions.Add("Hour", "HOUR({0})");
dateFunctions.Add("Minute", "MINUTE({0})");
dateFunctions.Add("Second", "SECOND({0})");
stringFunctions.Add("Concat", "CONCAT({0}, {1})");
stringFunctions.Add("IndexOf", "LOCATE({0}, {1})");
stringFunctions.Add("Left", "LEFT({0}, {1})");
stringFunctions.Add("Length", "LENGTH({0})");
stringFunctions.Add("LTrim", "LTRIM({0})");
stringFunctions.Add("Replace", "REPLACE({0}, {1}, {2})");
stringFunctions.Add("Reverse", "REVERSE({0})");
stringFunctions.Add("Right", "RIGHT({0}, {1})");
stringFunctions.Add("RTrim", "RTRIM({0})");
stringFunctions.Add("Substring", "SUBSTR({0}, {1}, {2})");
stringFunctions.Add("ToLower", "LOWER({0})");
stringFunctions.Add("ToUpper", "UPPER({0})");
stringFunctions.Add("Trim", "TRIM({0})");
mathFunctions.Add("Abs", "ABS({0})");
mathFunctions.Add("Ceiling", "CEILING({0})");
mathFunctions.Add("Floor", "FLOOR({0})");
mathFunctions.Add("Round", "ROUND");
}
public SqlFragment Generate(DbFunctionExpression e, SqlGenerator caller)
{
callingGenerator = caller;
if (bitwiseFunctions.ContainsKey(e.Function.Name))
return BitwiseFunction(e);
else if (dateFunctions.ContainsKey(e.Function.Name))
return GenericFunction(dateFunctions, e);
else if (stringFunctions.ContainsKey(e.Function.Name))
return GenericFunction(stringFunctions, e);
else if (mathFunctions.ContainsKey(e.Function.Name))
return GenericFunction(mathFunctions, e);
else
return UserDefinedFunction(e);
}
private SqlFragment UserDefinedFunction(DbFunctionExpression e)
{
FunctionFragment f = new FunctionFragment();
f.Name = Metadata.TryGetValueMetadataProperty<string>(e.Function,
"StoreFunctionNameAttribute");
if (String.IsNullOrEmpty(f.Name))
f.Name = e.Function.Name;
f.Quoted = !Metadata.TryGetValueMetadataProperty<bool>(e.Function, "BuiltInAttribute");
bool isFuncNiladic = Metadata.TryGetValueMetadataProperty<bool>(e.Function, "NiladicFunctionAttribute");
if (isFuncNiladic && e.Arguments.Count > 0)
throw new InvalidOperationException("Niladic functions cannot have parameters");
ListFragment list = new ListFragment();
string delimiter = "";
foreach (DbExpression arg in e.Arguments)
{
if (delimiter.Length > 0)
list.Append(new LiteralFragment(delimiter));
list.Append(arg.Accept(callingGenerator));
delimiter = ", ";
}
f.Argmument = list;
return f;
}
private SqlFragment BitwiseFunction(DbFunctionExpression e)
{
StringBuilder sql = new StringBuilder();
int arg = 0;
if (e.Arguments.Count > 1)
sql.AppendFormat("({0})", e.Arguments[arg++].Accept(callingGenerator));
sql.AppendFormat(" {0} ({1})", bitwiseFunctions[e.Function.Name],
e.Arguments[arg].Accept(callingGenerator));
return new LiteralFragment(sql.ToString());
}
private SqlFragment GenericFunction(Dictionary<string,string> funcs,
DbFunctionExpression e)
{
SqlFragment[] frags = new SqlFragment[e.Arguments.Count];
for (int i=0; i < e.Arguments.Count; i++)
frags[i] = e.Arguments[i].Accept(callingGenerator);
string sql;
switch (e.Function.Name)
{
case "Round":
// Special handling for Round as it has more than one signature.
sql = HandleFunctionRound(e);
break;
default:
sql = String.Format(funcs[e.Function.Name], frags);
break;
}
return new LiteralFragment(sql);
}
private string HandleFunctionRound(DbFunctionExpression e)
{
StringBuilder sqlBuilder = new StringBuilder();
sqlBuilder.Append(mathFunctions[e.Function.Name]);
sqlBuilder.Append("(");
Debug.Assert(e.Arguments.Count <= 2, "Round should have at most 2 arguments");
sqlBuilder.Append(e.Arguments[0].Accept(callingGenerator));
sqlBuilder.Append(", ");
if (e.Arguments.Count > 1)
{
sqlBuilder.Append(e.Arguments[1].Accept(callingGenerator));
}
else
{
sqlBuilder.Append("0");
}
sqlBuilder.Append(")");
return sqlBuilder.ToString();
}
}
}
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