SqlProviderManifest.cs source code in C# .NET

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/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / SqlClient / SqlProviderManifest.cs / 1305376 / SqlProviderManifest.cs

                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 
using System.Collections.Generic;
using System.Xml; 
using System.Collections.ObjectModel;
using System.Data.EntityModel.SchemaObjectModel;
using System.Data.EntityModel;
using System.Data.Common; 
using System.Diagnostics;
using System.Data.Entity; 
using System.Data.SqlClient; 
using System.Data.Metadata.Edm;
using System.Text; 

namespace System.Data.SqlClient
{
    ///  
    /// The Provider Manifest for SQL Server
    ///  
    internal class SqlProviderManifest : DbXmlEnabledProviderManifest 
    {
        internal const string TokenSql8 = "2000"; 
        internal const string TokenSql9 = "2005";
        internal const string TokenSql10 = "2008";

        // '~' is the same escape character that L2S uses 
        internal const char LikeEscapeChar = '~';
        internal const string LikeEscapeCharToString = "~"; 
 
        #region Private Fields
 
        // Default to SQL Server 2005 (9.0)
        private SqlVersion _version = SqlVersion.Sql9;

        ///  
        /// maximum size of sql server unicode
        ///  
        private const int varcharMaxSize = 8000; 
        private const int nvarcharMaxSize = 4000;
        private const int binaryMaxSize = 8000; 

        private System.Collections.ObjectModel.ReadOnlyCollection _primitiveTypes = null;
        private System.Collections.ObjectModel.ReadOnlyCollection _functions = null;
 
        #endregion
 
        #region Constructors 

        ///  
        /// Constructor
        /// 
        /// A token used to infer the capabilities of the store
        public SqlProviderManifest(string manifestToken) 
            : base(SqlProviderManifest.GetProviderManifest())
        { 
            // GetSqlVersion will throw ArgumentException if manifestToken is null, empty, or not recognized. 
            _version = SqlVersionUtils.GetSqlVersion(manifestToken);
        } 


        #endregion
 
        #region Properties
 
        internal SqlVersion SqlVersion 
        {
            get { return this._version; } 
        }

        #endregion
 
        #region Private Methods
        private static XmlReader GetProviderManifest() 
        { 
            return DbProviderServices.GetXmlResource("System.Data.Resources.SqlClient.SqlProviderServices.ProviderManifest.xml");
        } 

        private XmlReader GetStoreSchemaMapping()
        {
            return DbProviderServices.GetXmlResource("System.Data.Resources.SqlClient.SqlProviderServices.StoreSchemaMapping.msl"); 
        }
 
        private XmlReader GetStoreSchemaDescription() 
        {
            if (this._version == SqlVersion.Sql8) 
            {
                return DbProviderServices.GetXmlResource("System.Data.Resources.SqlClient.SqlProviderServices.StoreSchemaDefinition_Sql8.ssdl");
            }
 
            return DbProviderServices.GetXmlResource("System.Data.Resources.SqlClient.SqlProviderServices.StoreSchemaDefinition.ssdl");
        } 
        #endregion 

        #region Internal Methods 

        /// 
        /// Function to detect wildcard characters %, _, [ and ^ and escape them with a preceding ~
        /// This escaping is used when StartsWith, EndsWith and Contains canonical and CLR functions 
        /// are translated to their equivalent LIKE expression
        /// NOTE: This code has been copied from LinqToSql 
        ///  
        /// Original input as specified by the user
        /// escape the escape character ~ regardless whether wildcard 
        /// characters were encountered 
        /// true if the escaping was performed, false if no escaping was required
        /// The escaped string that can be used as pattern in a LIKE expression
        internal static string EscapeLikeText(string text, bool alwaysEscapeEscapeChar, out bool usedEscapeChar) 
        {
            usedEscapeChar = false; 
            if (!(text.Contains("%") || text.Contains("_") || text.Contains("[") 
                || text.Contains("^") || alwaysEscapeEscapeChar && text.Contains(LikeEscapeCharToString)))
            { 
                return text;
            }
            StringBuilder sb = new StringBuilder(text.Length);
            foreach (char c in text) 
            {
                if (c == '%' || c == '_' || c == '[' || c == '^' || c == LikeEscapeChar) 
                { 
                    sb.Append(LikeEscapeChar);
                    usedEscapeChar = true; 
                }
                sb.Append(c);
            }
            return sb.ToString(); 
        }
        #endregion 
 
        #region Overrides
        ///  
        /// Providers should override this to return information specific to their provider.
        ///
        /// This method should never return null.
        ///  
        /// The name of the information to be retrieved.
        /// An XmlReader at the begining of the information requested. 
        protected override XmlReader GetDbInformation(string informationType) 
        {
            if (informationType == DbProviderManifest.StoreSchemaDefinition) 
            {
                return GetStoreSchemaDescription();
            }
 
            if (informationType == DbProviderManifest.StoreSchemaMapping)
            { 
                return GetStoreSchemaMapping(); 
            }
 
            // Use default Conceptual Schema Definition
            if (informationType == DbProviderManifest.ConceptualSchemaDefinition)
            {
                return null; 
            }
 
            throw EntityUtil.ProviderIncompatible(System.Data.Entity.Strings.ProviderReturnedNullForGetDbInformation(informationType)); 
        }
 
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Globalization", "CA1308:NormalizeStringsToUppercase")]
        public override System.Collections.ObjectModel.ReadOnlyCollection GetStoreTypes()
        {
            if (this._primitiveTypes == null) 
            {
                if (this._version == SqlVersion.Sql10) 
                { 
                    this._primitiveTypes = base.GetStoreTypes();
                } 
                else
                {
                    List primitiveTypes = new List(base.GetStoreTypes());
                    Debug.Assert((this._version == SqlVersion.Sql8) || (this._version == SqlVersion.Sql9), "Found verion other than Sql 8, 9 or 10"); 
                    //Remove the Katmai types for both Sql8 and Sql9
                    primitiveTypes.RemoveAll(new Predicate( 
                                                        delegate(PrimitiveType primitiveType) 
                                                        {
                                                            string name = primitiveType.Name.ToLowerInvariant(); 
                                                            return name.Equals("time", StringComparison.Ordinal) ||
                                                                   name.Equals("date", StringComparison.Ordinal) ||
                                                                   name.Equals("datetime2", StringComparison.Ordinal) ||
                                                                   name.Equals("datetimeoffset", StringComparison.Ordinal); 
                                                        }
                                                    ) 
                                        ); 
                    //Remove the types that won't work in Sql8
                    if (this._version == SqlVersion.Sql8)                    { 

                        // SQLBUDT 550667 and 551271: Remove xml and 'max' types for SQL Server 2000
                        primitiveTypes.RemoveAll(new Predicate(
                                                            delegate(PrimitiveType primitiveType) 
                                                            {
                                                                string name = primitiveType.Name.ToLowerInvariant(); 
                                                                return name.Equals("xml", StringComparison.Ordinal) || name.EndsWith("(max)", StringComparison.Ordinal); 
                                                            }
                                                        ) 
                                            );
                    }
                    this._primitiveTypes = primitiveTypes.AsReadOnly();
                } 
            }
 
            return this._primitiveTypes; 
        }
 
        public override System.Collections.ObjectModel.ReadOnlyCollection GetStoreFunctions()
        {
            if (this._functions == null)
            { 
                if (this._version == SqlVersion.Sql10)
                { 
                    this._functions = base.GetStoreFunctions(); 
                }
                else 
                {
                    List functions = new List(base.GetStoreFunctions());
                    //Remove the functions over katmai types from both Sql 9 and Sql 10.
                    functions.RemoveAll(new Predicate( 
                                    delegate(EdmFunction edmFunction)
                                    { 
                                        ReadOnlyMetadataCollection funParams = edmFunction.Parameters; 
                                        switch (edmFunction.Name.ToUpperInvariant())
                                        { 
                                            case "COUNT":
                                            case "COUNT_BIG":
                                            case "MAX":
                                            case "MIN": 
                                                {
                                                    string name = ((CollectionType)funParams[0].TypeUsage.EdmType).TypeUsage.EdmType.Name; 
                                                    return ((name.Equals("DateTimeOffset", StringComparison.OrdinalIgnoreCase)) || 
                                                           (name.Equals("Time", StringComparison.OrdinalIgnoreCase)));
 
                                                }
                                            case "DAY":
                                            case "MONTH":
                                            case "YEAR": 
                                            case "DATALENGTH":
                                            case "CHECKSUM": 
                                                { 
                                                    string name = funParams[0].TypeUsage.EdmType.Name;
                                                    return ((name.Equals("DateTimeOffset", StringComparison.OrdinalIgnoreCase)) || 
                                                           (name.Equals("Time", StringComparison.OrdinalIgnoreCase)));

                                                }
                                            case "DATEADD": 
                                            case "DATEDIFF":
                                                { 
                                                    string param1Name = funParams[1].TypeUsage.EdmType.Name; 
                                                    string param2Name = funParams[2].TypeUsage.EdmType.Name;
                                                    return ( (param1Name.Equals("Time", StringComparison.OrdinalIgnoreCase)) || 
                                                           (param2Name.Equals("Time", StringComparison.OrdinalIgnoreCase)) ||
                                                           (param1Name.Equals("DateTimeOffset", StringComparison.OrdinalIgnoreCase)) ||
                                                           (param2Name.Equals("DateTimeOffset", StringComparison.OrdinalIgnoreCase)));
                                                } 
                                            case "DATENAME":
                                            case "DATEPART": 
                                                { 
                                                    string name = funParams[1].TypeUsage.EdmType.Name;
                                                    return ((name.Equals("DateTimeOffset", StringComparison.OrdinalIgnoreCase)) || 
                                                           (name.Equals("Time", StringComparison.OrdinalIgnoreCase)));
                                                }
                                            case "SYSUTCDATETIME":
                                            case "SYSDATETIME": 
                                            case "SYSDATETIMEOFFSET":
                                                return true; 
                                            default: 
                                                break;
                                        } 

                                        return false;
                                    }
                                ) 
                    );
 
 

                    if (this._version == SqlVersion.Sql8) 
                    {
                        // SQLBUDT 550998: Remove unsupported overloads from Provider Manifest on SQL 8.0
                        functions.RemoveAll(new Predicate(
                                                            delegate(EdmFunction edmFunction) 
                                                            {
                                                                ReadOnlyMetadataCollection funParams = edmFunction.Parameters; 
                                                                if (funParams == null || funParams.Count == 0) 
                                                                {
                                                                    return false; 
                                                                }

                                                                switch (edmFunction.Name.ToUpperInvariant())
                                                                { 
                                                                    case "COUNT":
                                                                    case "COUNT_BIG": 
                                                                        { 
                                                                            string name = ((CollectionType)funParams[0].TypeUsage.EdmType).TypeUsage.EdmType.Name;
                                                                            return name.Equals("Guid", StringComparison.OrdinalIgnoreCase); 
                                                                        }

                                                                    case "CHARINDEX":
                                                                        { 
                                                                            foreach (FunctionParameter funParam in funParams)
                                                                            { 
                                                                                if (funParam.TypeUsage.EdmType.Name.Equals("Int64", StringComparison.OrdinalIgnoreCase)) 
                                                                                {
                                                                                    return true; 
                                                                                }
                                                                            }
                                                                        }
                                                                        break; 

                                                                    default: 
                                                                        break; 
                                                                }
 
                                                                return false;
                                                            }
                                                        )
                                            ); 
                    }
                    this._functions = functions.AsReadOnly(); 
                } 
            }
 
            return this._functions;
        }

        ///  
        /// This method takes a type and a set of facets and returns the best mapped equivalent type
        /// in EDM. 
        ///  
        /// A TypeUsage encapsulating a store type and a set of facets
        /// A TypeUsage encapsulating an EDM type and a set of facets 
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Globalization", "CA1308:NormalizeStringsToUppercase")]
        public override TypeUsage GetEdmType(TypeUsage storeType)
        {
            EntityUtil.CheckArgumentNull(storeType, "storeType"); 

            string storeTypeName = storeType.EdmType.Name.ToLowerInvariant(); 
            if (!base.StoreTypeNameToEdmPrimitiveType.ContainsKey(storeTypeName)) 
            {
                throw EntityUtil.Argument(Strings.ProviderDoesNotSupportType(storeTypeName)); 
            }

            PrimitiveType edmPrimitiveType = base.StoreTypeNameToEdmPrimitiveType[storeTypeName];
 
            int maxLength = 0;
            bool isUnicode = true; 
            bool isFixedLen = false; 
            bool isUnbounded = true;
 
            PrimitiveTypeKind newPrimitiveTypeKind;

            switch (storeTypeName)
            { 
                // for some types we just go with simple type usage with no facets
                case "tinyint": 
                case "smallint": 
                case "bigint":
                case "bit": 
                case "uniqueidentifier":
                case "int":
                    return TypeUsage.CreateDefaultTypeUsage(edmPrimitiveType);
 
                case "varchar":
                    newPrimitiveTypeKind = PrimitiveTypeKind.String; 
                    isUnbounded = !TypeHelpers.TryGetMaxLength(storeType, out maxLength); 
                    isUnicode = false;
                    isFixedLen = false; 
                    break;

                case "char":
                    newPrimitiveTypeKind = PrimitiveTypeKind.String; 
                    isUnbounded = !TypeHelpers.TryGetMaxLength(storeType, out maxLength);
                    isUnicode = false; 
                    isFixedLen = true; 
                    break;
 
                case "nvarchar":
                    newPrimitiveTypeKind = PrimitiveTypeKind.String;
                    isUnbounded = !TypeHelpers.TryGetMaxLength(storeType, out maxLength);
                    isUnicode = true; 
                    isFixedLen = false;
                    break; 
 
                case "nchar":
                    newPrimitiveTypeKind = PrimitiveTypeKind.String; 
                    isUnbounded = !TypeHelpers.TryGetMaxLength(storeType, out maxLength);
                    isUnicode = true;
                    isFixedLen = true;
                    break; 

                case "varchar(max)": 
                case "text": 
                    newPrimitiveTypeKind = PrimitiveTypeKind.String;
                    isUnbounded = true; 
                    isUnicode = false;
                    isFixedLen = false;
                    break;
 
                case "nvarchar(max)":
                case "ntext": 
                case "xml": 
                    newPrimitiveTypeKind = PrimitiveTypeKind.String;
                    isUnbounded = true; 
                    isUnicode = true;
                    isFixedLen = false;
                    break;
 
                case "binary":
                    newPrimitiveTypeKind = PrimitiveTypeKind.Binary; 
                    isUnbounded = !TypeHelpers.TryGetMaxLength(storeType, out maxLength); 
                    isFixedLen = true;
                    break; 

                case "varbinary":
                    newPrimitiveTypeKind = PrimitiveTypeKind.Binary;
                    isUnbounded = !TypeHelpers.TryGetMaxLength(storeType, out maxLength); 
                    isFixedLen = false;
                    break; 
 
                case "varbinary(max)":
                case "image": 
                    newPrimitiveTypeKind = PrimitiveTypeKind.Binary;
                    isUnbounded = true;
                    isFixedLen = false;
                    break; 

                case "timestamp": 
                case "rowversion": 
                    return TypeUsage.CreateBinaryTypeUsage(edmPrimitiveType, true, 8);
 
                case "float":
                case "real":
                    return TypeUsage.CreateDefaultTypeUsage(edmPrimitiveType);
 
                case "decimal":
                case "numeric": 
                    { 
                        byte precision;
                        byte scale; 
                        if (TypeHelpers.TryGetPrecision(storeType, out precision) && TypeHelpers.TryGetScale(storeType, out scale))
                        {
                            return TypeUsage.CreateDecimalTypeUsage(edmPrimitiveType, precision, scale);
                        } 
                        else
                        { 
                            return TypeUsage.CreateDecimalTypeUsage(edmPrimitiveType); 
                        }
                    } 

                case "money":
                    return TypeUsage.CreateDecimalTypeUsage(edmPrimitiveType, 19, 4);
 
                case "smallmoney":
                    return TypeUsage.CreateDecimalTypeUsage(edmPrimitiveType, 10, 4); 
 
                case "datetime":
                case "datetime2": 
                case "smalldatetime":
                    return TypeUsage.CreateDateTimeTypeUsage(edmPrimitiveType, null);
                case "date":
                    return TypeUsage.CreateDefaultTypeUsage(edmPrimitiveType); 
                case "time":
                    return TypeUsage.CreateTimeTypeUsage(edmPrimitiveType, null); 
                case "datetimeoffset": 
                    return TypeUsage.CreateDateTimeOffsetTypeUsage(edmPrimitiveType, null);
 
                default:
                    throw EntityUtil.NotSupported(Strings.ProviderDoesNotSupportType(storeTypeName));
            }
 
            Debug.Assert(newPrimitiveTypeKind == PrimitiveTypeKind.String || newPrimitiveTypeKind == PrimitiveTypeKind.Binary, "at this point only string and binary types should be present");
 
            switch(newPrimitiveTypeKind) 
            {
                case PrimitiveTypeKind.String: 
                    if (!isUnbounded)
                    {
                        return TypeUsage.CreateStringTypeUsage(edmPrimitiveType, isUnicode, isFixedLen, maxLength);
                    } 
                    else
                    { 
                        return TypeUsage.CreateStringTypeUsage(edmPrimitiveType, isUnicode, isFixedLen); 
                    }
                case PrimitiveTypeKind.Binary: 
                    if (!isUnbounded)
                    {
                        return TypeUsage.CreateBinaryTypeUsage(edmPrimitiveType, isFixedLen, maxLength);
                    } 
                    else
                    { 
                        return TypeUsage.CreateBinaryTypeUsage(edmPrimitiveType, isFixedLen); 
                    }
                default: 
                    throw EntityUtil.NotSupported(Strings.ProviderDoesNotSupportType(storeTypeName));
            }
        }
 
        /// 
        /// This method takes a type and a set of facets and returns the best mapped equivalent type 
        /// in SQL Server, taking the store version into consideration. 
        /// 
        /// A TypeUsage encapsulating an EDM type and a set of facets 
        /// A TypeUsage encapsulating a store type and a set of facets
        public override TypeUsage GetStoreType(TypeUsage edmType)
        {
            EntityUtil.CheckArgumentNull(edmType, "edmType"); 
            System.Diagnostics.Debug.Assert(edmType.EdmType.BuiltInTypeKind == BuiltInTypeKind.PrimitiveType);
 
            PrimitiveType primitiveType = edmType.EdmType as PrimitiveType; 
            if (primitiveType == null)
            { 
                throw EntityUtil.Argument(Strings.ProviderDoesNotSupportType(edmType.Identity));
            }

            ReadOnlyMetadataCollection 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["bigint"]);
 
                case PrimitiveTypeKind.Guid:
                    return TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["uniqueidentifier"]); 
 
                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 (!TypeHelpers.TryGetPrecision(edmType, out precision))
                        { 
                            precision = 18;
                        }

                        byte scale; 
                        if (!TypeHelpers.TryGetScale(edmType, out scale))
                        { 
                            scale = 0; 
                        }
                        TypeUsage tu = TypeUsage.CreateDecimalTypeUsage(StoreTypeNameToStorePrimitiveType["decimal"], precision, scale); 
                        return tu;
                    }

                case PrimitiveTypeKind.Binary: // binary, varbinary, varbinary(max), image, timestamp, rowversion 
                    {
                        bool isFixedLength = null != facets[DbProviderManifest.FixedLengthFacetName].Value && (bool)facets[DbProviderManifest.FixedLengthFacetName].Value; 
                        Facet f = facets[DbProviderManifest.MaxLengthFacetName]; 
                        bool isMaxLength = Helper.IsUnboundedFacetValue(f) || null == f.Value || (int)f.Value > binaryMaxSize;
                        int maxLength = !isMaxLength ? (int)f.Value : Int32.MinValue; 

                        TypeUsage tu;
                        if (isFixedLength)
                        { 
                            tu = TypeUsage.CreateBinaryTypeUsage(StoreTypeNameToStorePrimitiveType["binary"], true, (isMaxLength ? binaryMaxSize : maxLength));
                        } 
                        else 
                        {
                            if (isMaxLength) 
                            {
                                if (_version != SqlVersion.Sql8)
                                {
 
                                    tu = TypeUsage.CreateBinaryTypeUsage(StoreTypeNameToStorePrimitiveType["varbinary(max)"], false);
                                    Debug.Assert(tu.Facets[DbProviderManifest.MaxLengthFacetName].Description.IsConstant, "varbinary(max) is not constant!"); 
                                } 
                                else
                                { 
                                    tu = TypeUsage.CreateBinaryTypeUsage(StoreTypeNameToStorePrimitiveType["varbinary"], false, binaryMaxSize);
                                }
                            }
                            else 
                            {
                                tu = TypeUsage.CreateBinaryTypeUsage(StoreTypeNameToStorePrimitiveType["varbinary"], false, maxLength); 
                            } 
                        }
                        return tu; 
                    }

                case PrimitiveTypeKind.String:
                    // char, nchar, varchar, nvarchar, varchar(max), nvarchar(max), ntext, text, xml 
                    {
                        bool isUnicode = null == facets[DbProviderManifest.UnicodeFacetName].Value || (bool)facets[DbProviderManifest.UnicodeFacetName].Value; 
                        bool isFixedLength = null != facets[DbProviderManifest.FixedLengthFacetName].Value && (bool)facets[DbProviderManifest.FixedLengthFacetName].Value; 
                        Facet f = facets[DbProviderManifest.MaxLengthFacetName];
                        // maxlen is true if facet value is unbounded, the value is bigger than the limited string sizes *or* the facet 
                        // value is null. this is needed since functions still have maxlength facet value as null
                        bool isMaxLength = Helper.IsUnboundedFacetValue(f) || null == f.Value || (int)f.Value > (isUnicode ? nvarcharMaxSize : varcharMaxSize);
                        int maxLength = !isMaxLength ? (int)f.Value : Int32.MinValue;
 
                        TypeUsage tu;
 
                        if (isUnicode) 
                        {
                            if (isFixedLength) 
                            {
                                tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["nchar"], true, true, (isMaxLength ? nvarcharMaxSize : maxLength));
                            }
                            else 
                            {
                                if (isMaxLength) 
                                { 
                                    // nvarchar(max) (SQL 9) or ntext (SQL 8)
                                    if (_version != SqlVersion.Sql8) 
                                    {
                                        tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["nvarchar(max)"], true, false);
                                        Debug.Assert(tu.Facets[DbProviderManifest.MaxLengthFacetName].Description.IsConstant, "NVarchar(max) is not constant!");
                                    } 
                                    else
                                    { 
                                        // if it is unknown, fallback to nvarchar[4000] instead of ntext since it has limited store semantics 
                                        tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["nvarchar"], true, false, nvarcharMaxSize);
                                    } 
                                }
                                else
                                {
                                    tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["nvarchar"], true, false, maxLength); 
                                }
                            } 
                        } 
                        else    // !isUnicode
                        { 
                            if (isFixedLength)
                            {
                                tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["char"], false, true,
                                    (isMaxLength ? varcharMaxSize : maxLength)); 
                            }
                            else 
                            { 
                                if (isMaxLength)
                                { 
                                    // nvarchar(max) (SQL 9) or ntext (SQL 8)
                                    if (_version != SqlVersion.Sql8)
                                    {
                                        tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["varchar(max)"], false, false); 
                                        Debug.Assert(tu.Facets[DbProviderManifest.MaxLengthFacetName].Description.IsConstant, "varchar(max) is not constant!");
                                    } 
                                    else 
                                    {
                                        // if it is unknown, fallback to varchar[8000] instead of text since it has limited store semantics 
                                        tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["varchar"], false, false, varcharMaxSize);
                                    }
                                }
                                else 
                                {
                                    tu = TypeUsage.CreateStringTypeUsage(StoreTypeNameToStorePrimitiveType["varchar"], false, false, maxLength); 
                                } 
                            }
                        } 
                        return tu;
                    }

 
                case PrimitiveTypeKind.DateTime:
                    return TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["datetime"]); 
                case PrimitiveTypeKind.DateTimeOffset: 
                    //No DateTimeOffset type in Sql8 or Sql9
                    if ((this.SqlVersion != SqlVersion.Sql8) && (this.SqlVersion != SqlVersion.Sql9)) 
                    {
                        return TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["datetimeoffset"]);
                    }
                    else 
                    {
                        throw EntityUtil.NotSupported(Strings.NoStoreTypeForEdmType(edmType.Identity, primitiveType.PrimitiveTypeKind)); 
                    } 
                case PrimitiveTypeKind.Time:
                    //No Time type in Sql8 or Sql9 
                    if ((this.SqlVersion != SqlVersion.Sql8) && (this.SqlVersion != SqlVersion.Sql9))
                    {
                        return TypeUsage.CreateDefaultTypeUsage(StoreTypeNameToStorePrimitiveType["time"]);
                    } 
                    else
                    { 
                        throw EntityUtil.NotSupported(Strings.NoStoreTypeForEdmType(edmType.Identity, primitiveType.PrimitiveTypeKind)); 
                    }
                default: 
                    throw EntityUtil.NotSupported(Strings.NoStoreTypeForEdmType(edmType.Identity, primitiveType.PrimitiveTypeKind));
            }
        }
 
        /// 
        /// Returns true, SqlClient supports escaping strings to be used as arguments to like 
        /// The escape character is '~' 
        /// 
        /// The character '~' 
        /// True
        public override bool SupportsEscapingLikeArgument(out char escapeCharacter)
        {
            escapeCharacter = SqlProviderManifest.LikeEscapeChar; 
            return true;
        } 
 
        /// 
        /// Escapes the wildcard characters and the escape character in the given argument. 
        /// 
        /// 
        /// Equivalent to the argument, with the wildcard characters and the escape character escaped
        public override string EscapeLikeArgument(string argument) 
        {
            bool usedEscapeCharacter; 
            return SqlProviderManifest.EscapeLikeText(argument, true, out usedEscapeCharacter); 
        }
        #endregion 
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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