/// <summary>
/// Chooses the appropriate DbType for the given string type.
/// </summary>
private static DbType GetStringDbType(TypeUsage type)
{
Debug.Assert(type.EdmType.BuiltInTypeKind == BuiltInTypeKind.PrimitiveType &&
PrimitiveTypeKind.String == ((PrimitiveType)type.EdmType).PrimitiveTypeKind, "only valid for string type");
DbType dbType;
// Specific type depends on whether the string is a unicode string and whether it is a fixed length string.
// By default, assume widest type (unicode) and most common type (variable length)
bool unicode;
bool fixedLength;
if (!type.TryGetIsFixedLength(out fixedLength))
{
fixedLength = false;
}
unicode = type.GetIsUnicode();
if (fixedLength)
{
dbType = (unicode ? DbType.StringFixedLength : DbType.AnsiStringFixedLength);
}
else
{
dbType = (unicode ? DbType.String : DbType.AnsiString);
}
return(dbType);
}
/// <summary>
/// Chooses the appropriate OleDbType for the given string type.
/// </summary>
private static OleDbType GetStringDbType(TypeUsage tu)
{
if (tu.EdmType.BuiltInTypeKind != BuiltInTypeKind.PrimitiveType || PrimitiveTypeKind.String != ((PrimitiveType)tu.EdmType).PrimitiveTypeKind)
{
throw new ArgumentException("GetStringDbType require a TypeUsage of string type", "tu");
}
OleDbType dbType;
if (tu.EdmType.Name.ToLowerInvariant() == "xml")
{
// JET: dbType = OleDbType.Xml;
dbType = OleDbType.LongVarChar;
}
else
{
// Specific type depends on whether the string is a unicode string and whether it is a fixed length string.
// By default, assume widest type (unicode) and most common type (variable length)
bool unicode;
bool fixedLength;
if (!tu.TryGetIsFixedLength(out fixedLength))
{
fixedLength = false;
}
unicode = tu.GetIsUnicode(); // This should change return type to NVarChar/NChar but in Jet everything is in unicode
if (fixedLength)
{
dbType = OleDbType.Char;
}
else
{
dbType = OleDbType.VarChar;
}
}
return(dbType);
}
/// <summary>
/// This method takes a type and a set of facets and returns the best mapped equivalent type
/// in Jet
/// </summary>
/// <param name="storeType">A TypeUsage encapsulating an EDM type and a set of facets</param>
/// <returns>A TypeUsage encapsulating a store type and a set of facets</returns>
public override TypeUsage GetStoreType(TypeUsage edmType)
{
if (edmType == null)
{
throw new ArgumentNullException("edmType");
}
System.Diagnostics.Debug.Assert(edmType.EdmType.BuiltInTypeKind == BuiltInTypeKind.PrimitiveType);
PrimitiveType primitiveType = edmType.EdmType as PrimitiveType;
if (primitiveType == null)
{
throw new ArgumentException(String.Format("The underlying provider does not support the type '{0}'.", edmType));
}
ReadOnlyMetadataCollection <Facet> facets = edmType.Facets;
switch (primitiveType.PrimitiveTypeKind)
{
case PrimitiveTypeKind.Boolean:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["bit"]));
case PrimitiveTypeKind.Byte:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["tinyint"]));
case PrimitiveTypeKind.Int16:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["smallint"]));
case PrimitiveTypeKind.Int32:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["int"]));
case PrimitiveTypeKind.Int64:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["int"]));
case PrimitiveTypeKind.Guid:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["guid"]));
case PrimitiveTypeKind.Double:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["float"]));
case PrimitiveTypeKind.Single:
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["real"]));
case PrimitiveTypeKind.Decimal: // decimal, numeric, smallmoney, money
{
byte precision;
if (!edmType.TryGetPrecision(out precision))
{
precision = 18;
}
byte scale;
if (!edmType.TryGetScale(out scale))
{
scale = 0;
}
return(TypeUsage.CreateDecimalTypeUsage(StoreTypeNameToStorePrimitiveType["decimal"], precision, scale));
}
case PrimitiveTypeKind.Binary: // binary, varbinary, image
{
bool isFixedLength = edmType.GetIsFixedLength();
bool isMaxLength = edmType.GetMaxLength() > BINARY_MAXSIZE;
int maxLength = edmType.GetMaxLength();
TypeUsage tu;
if (isFixedLength)
{
tu = TypeUsage.CreateBinaryTypeUsage(StoreTypeNameToStorePrimitiveType["binary"], true, maxLength);
}
else if (isMaxLength)
{
tu = TypeUsage.CreateBinaryTypeUsage(StoreTypeNameToStorePrimitiveType["image"], false);
System.Diagnostics.Debug.Assert(tu.Facets["MaxLength"].Description.IsConstant, "varbinary(max) is not constant!");
}
else
{
tu = TypeUsage.CreateBinaryTypeUsage(StoreTypeNameToStorePrimitiveType["varbinary"], false, maxLength);
}
return(tu);
}
case PrimitiveTypeKind.String:
// char, varchar, text
{
bool isUnicode = edmType.GetIsUnicode(); // We do not handle unicode (everything's unicode in Jet)
bool isFixedLength = edmType.GetIsFixedLength();
bool isMaxLength = edmType.GetMaxLength() > VARCHAR_MAXSIZE;
int maxLength = edmType.GetMaxLength();
TypeUsage tu;
if (isFixedLength)
{
tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["char"], false, true, maxLength);
}
else if (isMaxLength)
{
tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["text"], false, false);
}
else
{
tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["varchar"], false, false, maxLength);
}
return(tu);
}
case PrimitiveTypeKind.DateTime: // datetime
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["datetime"]));
case PrimitiveTypeKind.Time: // time
return(TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["time"]));
default:
throw new NotSupportedException(String.Format("There is no store type corresponding to the EDM type '{0}' of primitive type '{1}'.", edmType, primitiveType.PrimitiveTypeKind));
}
}