EntityParameter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / EntityClient / EntityParameter.cs / 1305376 / EntityParameter.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 
using System.Collections.Generic;
using System.Text; 
using System.Data;
using System.Data.Common;
using System.Data.Common.CommandTrees;
using System.Data.Common.Internal; 
using System.Data.Metadata.Edm;
using System.Text.RegularExpressions; 
using System.Diagnostics; 

namespace System.Data.EntityClient 
{
    /// 
    /// Class representing a parameter used in EntityCommand
    ///  
    public sealed partial class EntityParameter : DbParameter, IDbDataParameter
    { 
        private string _parameterName; 
        private DbType? _dbType;
        private byte? _precision; 
        private byte? _scale;
        private bool _isDirty;

        ///  
        /// Constructs the EntityParameter object
        ///  
        public EntityParameter() 
        {
        } 

        /// 
        /// Constructs the EntityParameter object with the given parameter name and the type of the parameter
        ///  
        /// The name of the parameter
        /// The type of the parameter 
        public EntityParameter(string parameterName, DbType dbType) 
        {
            SetParameterNameWithValidation(parameterName, "parameterName"); 
            this.DbType = dbType;
        }

        ///  
        /// Constructs the EntityParameter object with the given parameter name, the type of the parameter, and the size of the
        /// parameter 
        ///  
        /// The name of the parameter
        /// The type of the parameter 
        /// The size of the parameter
        public EntityParameter(string parameterName, DbType dbType, int size)
        {
            SetParameterNameWithValidation(parameterName, "parameterName"); 
            this.DbType = dbType;
            this.Size = size; 
        } 

        ///  
        /// Constructs the EntityParameter object with the given parameter name, the type of the parameter, the size of the
        /// parameter, and the name of the source column
        /// 
        /// The name of the parameter 
        /// The type of the parameter
        /// The size of the parameter 
        /// The name of the source column mapped to the data set, used for loading the parameter value 
        public EntityParameter(string parameterName, DbType dbType, int size, string sourceColumn)
        { 
            SetParameterNameWithValidation(parameterName, "parameterName");
            this.DbType = dbType;
            this.Size = size;
            this.SourceColumn = sourceColumn; 
        }
 
        ///  
        /// Constructs the EntityParameter object with the given parameter name, the type of the parameter, the size of the
        /// parameter, and the name of the source column 
        /// 
        /// The name of the parameter
        /// The type of the parameter
        /// The size of the parameter 
        /// The direction of the parameter, whether it's input/output/both/return value
        /// If the parameter is nullable 
        /// The floating point precision of the parameter, valid only if the parameter type is a floating point type 
        /// The scale of the parameter, valid only if the parameter type is a floating point type
        /// The name of the source column mapped to the data set, used for loading the parameter value 
        /// The data row version to use when loading the parameter value
        /// The value of the parameter
        public EntityParameter(string parameterName,
                            DbType dbType, 
                            int size,
                            ParameterDirection direction, 
                            bool isNullable, 
                            byte precision,
                            byte scale, 
                            string sourceColumn,
                            DataRowVersion sourceVersion,
                            object value)
        { 
            SetParameterNameWithValidation(parameterName, "parameterName");
            this.DbType = dbType; 
            this.Size = size; 
            this.Direction = direction;
            this.IsNullable = isNullable; 
            this.Precision = precision;
            this.Scale = scale;
            this.SourceColumn = sourceColumn;
            this.SourceVersion = sourceVersion; 
            this.Value = value;
        } 
 
        /// 
        /// The name of the parameter 
        /// 
        public override string ParameterName
        {
            get 
            {
                return this._parameterName ?? ""; 
            } 
            set
            { 
                SetParameterNameWithValidation(value, "value");
            }
        }
 
        /// 
        /// Helper method to validate the parameter name; Ideally we'd only call this once, but 
        /// we have to put an argumentName on the Argument exception, and the property setter would 
        /// need "value" which confuses folks when they call the constructor that takes the value
        /// of the parameter.  c'est la vie. 
        /// 
        /// 
        /// 
        private void SetParameterNameWithValidation(string parameterName, string argumentName) 
        {
            if (!string.IsNullOrEmpty(parameterName) && !DbCommandTree.IsValidParameterName(parameterName)) 
            { 
                throw EntityUtil.Argument(System.Data.Entity.Strings.EntityClient_InvalidParameterName(parameterName), argumentName);
            } 
            PropertyChanging();
            this._parameterName = parameterName;
        }
 
        /// 
        /// The type of the parameter 
        ///  
        public override DbType DbType
        { 
            get
            {
                // If the user hasn't set the DbType, then we deduce it from the value, but we won't set it in the
                // member field as it's used to keep track of what the user set explicitly 
                if (!this._dbType.HasValue)
                { 
                    // If we can't deduce the type as there are no values, just assume it's string type 
                    if (_value == null)
                        return DbType.String; 

                    try
                    {
                        return TypeHelpers.ConvertClrTypeToDbType(_value.GetType()); 
                    }
                    catch (ArgumentException e) 
                    { 
                        throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.EntityClient_CannotDeduceDbType, e);
                    } 
                }

                return (DbType)this._dbType;
            } 
            set
            { 
                PropertyChanging(); 
                this._dbType = value;
            } 
        }

        /// 
        /// The precision of the parameter if the parameter is a floating point type 
        /// 
        public byte Precision 
        { 
            get
            { 
                byte result = this._precision.HasValue ? this._precision.Value : (byte)0;
                return result;
            }
            set 
            {
                PropertyChanging(); 
                this._precision = value; 
            }
        } 

        /// 
        /// The scale of the parameter if the parameter is a floating point type
        ///  
        public byte Scale
        { 
            get 
            {
                byte result = this._scale.HasValue ? this._scale.Value : (byte)0; 
                return result;
            }
            set
            { 
                PropertyChanging();
                this._scale = value; 
            } 
        }
 
        /// 
        /// The value of the parameter
        /// 
        public override object Value 
        {
            get 
            { 
                return this._value;
            } 
            set
            {
                // If the user hasn't set the DbType, then we have to figure out if the DbType will change as a result
                // of the change in the value.  What we want to achieve is that changes to the value will not cause 
                // it to be dirty, but changes to the value that causes the apparent DbType to change, then should be
                // dirty. 
                if (!this._dbType.HasValue) 
                {
                    // If the value is null, then we assume it's string type 
                    DbType oldDbType = DbType.String;
                    if (_value != null)
                    {
                        oldDbType = TypeHelpers.ConvertClrTypeToDbType(_value.GetType()); 
                    }
 
                    // If the value is null, then we assume it's string type 
                    DbType newDbType = DbType.String;
                    if (value != null) 
                    {
                        newDbType = TypeHelpers.ConvertClrTypeToDbType(value.GetType());
                    }
 
                    if (oldDbType != newDbType)
                    { 
                        PropertyChanging(); 
                    }
                } 

                this._value = value;
            }
        } 

        ///  
        /// Gets whether this collection has been changes since the last reset 
        /// 
        internal bool IsDirty 
        {
            get
            {
                return _isDirty; 
            }
        } 
 
        /// 
        /// Indicates whether the DbType property has been set by the user; 
        /// 
        internal bool IsDbTypeSpecified
        {
            get 
            {
                return this._dbType.HasValue; 
            } 
        }
 
        /// 
        /// Indicates whether the Direction property has been set by the user;
        /// 
        internal bool IsDirectionSpecified 
        {
            get 
            { 
                return this._direction != 0;
            } 
        }

        /// 
        /// Indicates whether the IsNullable property has been set by the user; 
        /// 
        internal bool IsIsNullableSpecified 
        { 
            get
            { 
                return this._isNullable.HasValue;
            }
        }
 
        /// 
        /// Indicates whether the Precision property has been set by the user; 
        ///  
        internal bool IsPrecisionSpecified
        { 
            get
            {
                return this._precision.HasValue;
            } 
        }
 
        ///  
        /// Indicates whether the Scale property has been set by the user;
        ///  
        internal bool IsScaleSpecified
        {
            get
            { 
                return this._scale.HasValue;
            } 
        } 

        ///  
        /// Indicates whether the Size property has been set by the user;
        /// 
        internal bool IsSizeSpecified
        { 
            get
            { 
                return this._size.HasValue; 
            }
        } 

        /// 
        /// Resets the DbType property to its original settings
        ///  
        public override void ResetDbType()
        { 
            if (_dbType != null) 
            {
                PropertyChanging(); 
            }

            _dbType = null;
        } 

        ///  
        /// Clones this parameter object 
        /// 
        /// The new cloned object 
        internal EntityParameter Clone()
        {
            return new EntityParameter(this);
        } 

        ///  
        /// Clones this parameter object 
        /// 
        /// The new cloned object 
        private void CloneHelper(EntityParameter destination)
        {
            CloneHelperCore(destination);
 
            destination._parameterName = _parameterName;
            destination._dbType = _dbType; 
            destination._precision = _precision; 
            destination._scale = _scale;
        } 

        /// 
        /// Marks that this parameter has been changed
        ///  
        private void PropertyChanging()
        { 
            _isDirty = true; 
        }
 
        /// 
        /// Determines the size of the given object
        /// 
        ///  
        /// 
        private int ValueSize(object value) 
        { 
            return ValueSizeCore(value);
        } 

        /// 
        /// Get the type usage for this parameter in model terms.
        ///  
        /// The type usage for this parameter
        //NOTE: Because GetTypeUsage throws CommandValidationExceptions, it should only be called from EntityCommand during command execution 
        internal TypeUsage GetTypeUsage() 
        {
            TypeUsage typeUsage; 
            if (!DbTypeMap.TryGetModelTypeUsage(this.DbType, out typeUsage))
            {
                throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.EntityClient_UnsupportedDbType(this.DbType.ToString(), ParameterName));
            } 

            Debug.Assert(typeUsage != null, "DbType.TryGetModelTypeUsage returned true for null TypeUsage?"); 
            return typeUsage; 
        }
 
        /// 
        /// Reset the dirty flag on the collection
        /// 
        internal void ResetIsDirty() 
        {
            _isDirty = false; 
        } 
    }
} 

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

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