static bool TryGetCastTargetDbTypeString(Type sourceType, Type targetType, out string dbTypeString, bool throwNotSupportedException = true)
{
dbTypeString = null;
sourceType = ReflectionExtension.GetUnderlyingType(sourceType);
targetType = ReflectionExtension.GetUnderlyingType(targetType);
if (sourceType == targetType)
{
return(false);
}
if (CastTypeMap.TryGetValue(targetType, out dbTypeString))
{
return(true);
}
if (throwNotSupportedException)
{
throw new NotSupportedException(AppendNotSupportedCastErrorMsg(sourceType, targetType));
}
else
{
return(false);
}
}
public static void Aggregate_Average(SqlGenerator generator, DbExpression exp, Type retType)
{
string targetDbType = null;
Type underlyingType = ReflectionExtension.GetUnderlyingType(retType);
if (underlyingType != exp.Type.GetUnderlyingType())
{
CastTypeMap.TryGetValue(underlyingType, out targetDbType);
}
generator._sqlBuilder.Append("AVG", "(");
if (string.IsNullOrEmpty(targetDbType))
{
exp.Accept(generator);
}
else
{
generator._sqlBuilder.Append("CAST(");
exp.Accept(generator);
generator._sqlBuilder.Append(" AS ", targetDbType, ")");
}
generator._sqlBuilder.Append(")");
}
static bool TryGetCastTargetDbTypeString(Type sourceType, Type targetType, out string dbTypeString, bool throwNotSupportedException = true)
{
dbTypeString = null;
sourceType = ReflectionExtension.GetUnderlyingType(sourceType);
targetType = ReflectionExtension.GetUnderlyingType(targetType);
if (sourceType == targetType)
return false;
if (targetType == UtilConstants.TypeOfDecimal)
{
//Casting to Decimal is not supported when missing the precision and scale information.I have no idea to deal with this case now.
if (sourceType != UtilConstants.TypeOfInt16 && sourceType != UtilConstants.TypeOfInt32 && sourceType != UtilConstants.TypeOfInt64 && sourceType != UtilConstants.TypeOfByte)
{
if (throwNotSupportedException)
throw new NotSupportedException(AppendNotSupportedCastErrorMsg(sourceType, targetType));
else
return false;
}
}
if (CastTypeMap.TryGetValue(targetType, out dbTypeString))
{
return true;
}
if (throwNotSupportedException)
throw new NotSupportedException(AppendNotSupportedCastErrorMsg(sourceType, targetType));
else
return false;
}
static void AppendAggregateFunction(SqlGenerator generator, DbExpression exp, Type retType, string functionName, bool withCast)
{
string dbTypeString = null;
if (withCast == true)
{
Type underlyingType = ReflectionExtension.GetUnderlyingType(retType);
if (CastTypeMap.TryGetValue(underlyingType, out dbTypeString))
{
generator._sqlBuilder.Append("CAST(");
}
}
generator._sqlBuilder.Append(functionName, "(");
exp.Accept(generator);
generator._sqlBuilder.Append(")");
if (dbTypeString != null)
{
generator._sqlBuilder.Append(" AS ", dbTypeString, ")");
}
}
static void AppendAggregateFunction(SqlGenerator generator, DbExpression exp, Type retType, string functionName, bool withCast)
{
string dbTypeString = null;
if (withCast == true)
{
Type underlyingType = ReflectionExtension.GetUnderlyingType(retType);
if (underlyingType != PublicConstants.TypeOfDecimal /* We don't know the precision and scale,so,we can not cast exp to decimal,otherwise maybe cause problems. */ && CastTypeMap.TryGetValue(underlyingType, out dbTypeString))
{
generator._sqlBuilder.Append("CAST(");
}
}
generator._sqlBuilder.Append(functionName, "(");
exp.Accept(generator);
generator._sqlBuilder.Append(")");
if (dbTypeString != null)
{
generator._sqlBuilder.Append(" AS ", dbTypeString, ")");
}
}