DbCommandDefinition.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Common / DbCommandDefinition.cs / 1305376 / DbCommandDefinition.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....]
// @backupOwner [....] 
//----------------------------------------------------------------------------- 

using System.Diagnostics; 
using System.Data.Metadata.Edm;

namespace System.Data.Common {
 
    /// 
    /// A prepared command definition, can be cached and reused to avoid 
    /// repreparing a command. 
    /// 
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "Db")] 
    public class DbCommandDefinition {

        private readonly ICloneable _prototype;
 
        /// 
        /// Internal factory method to create the default Command Definition object 
        /// based on a prototype command. The prototype command is cloned 
        /// before the protected constructor is invoked
        ///  
        /// prototype DbCommand
        /// the DbCommandDefinition
        internal static DbCommandDefinition CreateCommandDefinition(DbCommand prototype) {
            EntityUtil.CheckArgumentNull(prototype, "prototype"); 
            ICloneable cloneablePrototype = prototype as ICloneable;
            if (null == cloneablePrototype) { 
                throw EntityUtil.CannotCloneStoreProvider(); 
            }
            DbCommand clonedPrototype = (DbCommand)(cloneablePrototype.Clone()); 
            return new DbCommandDefinition(clonedPrototype);
        }

        ///  
        /// Protected constructor; the command is assumed to be a prototype
        /// that will be cloned on CreateCommand, and the cloned command will be executed. 
        ///  
        protected DbCommandDefinition(DbCommand prototype) {
            EntityUtil.CheckArgumentNull(prototype, "prototype"); 
            _prototype = prototype as ICloneable;
            if (null == _prototype) {
                throw EntityUtil.CannotCloneStoreProvider();
            } 
        }
 
        ///  
        /// Constructor overload for subclasses to use
        ///  
        protected DbCommandDefinition() {
        }

        ///  
        /// Create a DbCommand object from the definition, that can be executed.
        ///  
        ///  
        public virtual DbCommand CreateCommand() {
            return (DbCommand)(_prototype.Clone()); 
        }

        internal static void PopulateParameterFromTypeUsage(DbParameter parameter, TypeUsage type, bool isOutParam)
        { 
            EntityUtil.CheckArgumentNull(parameter, "parameter");
            EntityUtil.CheckArgumentNull(type, "type"); 
 
            // parameter.IsNullable - from the NullableConstraintAttribute value
            parameter.IsNullable = TypeSemantics.IsNullable(type); 

            // parameter.ParameterName - set by the caller;
            // parameter.SourceColumn - not applicable until we have a data adapter;
            // parameter.SourceColumnNullMapping - not applicable until we have a data adapter; 
            // parameter.SourceVersion - not applicable until we have a data adapter;
            // parameter.Value - left unset; 
            // parameter.DbType - determined by the TypeMapping; 
            // parameter.Precision - from the TypeMapping;
            // parameter.Scale - from the TypeMapping; 
            // parameter.Size - from the TypeMapping;

            Debug.Assert(null != type, "no type mapping?");
 
            if (TypeSemantics.IsPrimitiveType(type, Metadata.Edm.PrimitiveTypeKind.Binary))
            { 
                PopulateBinaryParameter(parameter, type, DbType.Binary, isOutParam); 
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Boolean)) 
            {
                parameter.DbType = DbType.Boolean;
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Byte)) 
            {
                parameter.DbType = DbType.Byte; 
            } 
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.DateTime))
            { 
                PopulateDateTimeParameter(parameter, type, DbType.DateTime);
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Time))
            { 
                PopulateDateTimeParameter(parameter, type, DbType.Time);
            } 
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.DateTimeOffset)) 
            {
                PopulateDateTimeParameter(parameter, type, DbType.DateTimeOffset); 
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Decimal))
            {
                PopulateDecimalParameter(parameter, type, DbType.Decimal); 
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Double)) 
            { 
                parameter.DbType = DbType.Double;
            } 
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Guid))
            {
                parameter.DbType = DbType.Guid;
            } 
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Single))
            { 
                parameter.DbType = DbType.Single; 
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.SByte)) 
            {
                parameter.DbType = DbType.SByte;
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Int16)) 
            {
                parameter.DbType = DbType.Int16; 
            } 
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Int32))
            { 
                parameter.DbType = DbType.Int32;
            }
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.Int64))
            { 
                parameter.DbType = DbType.Int64;
            } 
            else if (TypeSemantics.IsPrimitiveType(type, PrimitiveTypeKind.String)) 
            {
                PopulateStringParameter(parameter, type, isOutParam); 
            }
        }

        private static void PopulateBinaryParameter(DbParameter parameter, TypeUsage type, DbType dbType, bool isOutParam) 
        {
            parameter.DbType = dbType; 
 
            // For each facet, set the facet value only if we have it, note that it's possible to not have
            // it in the case the facet value is null 
            SetParameterSize(parameter, type, isOutParam);
        }

        private static void PopulateDecimalParameter (DbParameter parameter, TypeUsage type, DbType dbType) 
        {
            parameter.DbType = dbType; 
            IDbDataParameter dataParameter = (IDbDataParameter)parameter; 

            // For each facet, set the facet value only if we have it, note that it's possible to not have 
            // it in the case the facet value is null
            byte precision;
            byte scale;
            if (TypeHelpers.TryGetPrecision(type, out precision)) 
            {
                dataParameter.Precision = precision; 
            } 

            if (TypeHelpers.TryGetScale(type, out scale)) 
            {
                dataParameter.Scale = scale;
            }
        } 

        private static void PopulateDateTimeParameter(DbParameter parameter, TypeUsage type, DbType dbType) 
        { 
            parameter.DbType = dbType;
            IDbDataParameter dataParameter = (IDbDataParameter)parameter; 

            // For each facet, set the facet value only if we have it, note that it's possible to not have
            // it in the case the facet value is null
            byte precision; 
            if (TypeHelpers.TryGetPrecision(type, out precision))
            { 
                dataParameter.Precision = precision; 
            }
        } 


        private static void PopulateStringParameter(DbParameter parameter, TypeUsage type, bool isOutParam)
        { 
            // For each facet, set the facet value only if we have it, note that it's possible to not have
            // it in the case the facet value is null 
            bool unicode = true; 
            bool fixedLength = false;
 
            if (!TypeHelpers.TryGetIsFixedLength(type, out fixedLength))
            {
                // If we can't get the fixed length facet value, then default to fixed length = false
                fixedLength = false; 
            }
 
            if (!TypeHelpers.TryGetIsUnicode(type, out unicode)) 
            {
                // If we can't get the unicode facet value, then default to unicode = true 
                unicode = true;
            }

            if (fixedLength) 
            {
                parameter.DbType = (unicode ? DbType.StringFixedLength : DbType.AnsiStringFixedLength); 
            } 
            else
            { 
                parameter.DbType = (unicode ? DbType.String : DbType.AnsiString);
            }

            SetParameterSize(parameter, type, isOutParam); 
        }
 
        private static void SetParameterSize(DbParameter parameter, TypeUsage type, bool isOutParam) 
        {
            // only set the size if the parameter has a specific size value. 
            Facet maxLengthFacet;
            if (type.Facets.TryGetValue(DbProviderManifest.MaxLengthFacetName, true, out maxLengthFacet) && maxLengthFacet.Value != null)
            {
                // only set size if there is a specific size 
                if (!Helper.IsUnboundedFacetValue(maxLengthFacet))
                { 
                    parameter.Size = (int)maxLengthFacet.Value; 
                }
                else if (isOutParam) 
                {
                    // if it is store procedure parameter and it is unbounded set the size to max
                    parameter.Size = Int32.MaxValue;
                } 
            }
        } 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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DbCommandDefinition.cs source code in C# .NET

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