/// <summary>
/// Check if value of specific field is already exist
/// </summary>
/// <typeparam name="E"></typeparam>
/// <param name="fieldName">name of the Field</param>
/// <param name="fieldValue">Field value</param>
/// <param name="key">Primary key value</param>
/// <returns>True or False</returns>
public bool TrySameValueExist(string fieldName, object fieldValue, string key)
{
// First we define the parameter that we are going to use the clause.
var xParam = Expression.Parameter(typeof(E), typeof(E).Name);
MemberExpression leftExprFieldCheck =
MemberExpression.Property(xParam, fieldName);
Expression rightExprFieldCheck = Expression.Constant(fieldValue);
BinaryExpression binaryExprFieldCheck =
MemberExpression.Equal(leftExprFieldCheck, rightExprFieldCheck);
MemberExpression leftExprKeyCheck =
MemberExpression.Property(xParam, this._KeyProperty);
Expression rightExprKeyCheck = Expression.Constant(key);
BinaryExpression binaryExprKeyCheck =
MemberExpression.NotEqual(leftExprKeyCheck, rightExprKeyCheck);
BinaryExpression finalBinaryExpr =
Expression.And(binaryExprFieldCheck, binaryExprKeyCheck);
//Create Lambda Expression for the selection
Expression <Func <E, bool> > lambdaExpr =
Expression.Lambda <Func <E, bool> >(finalBinaryExpr,
new ParameterExpression[] { xParam });
//Searching ....
return(_ctx.CreateQuery <E>("[" + this.GetEntitySetName(typeof(E).Name) + "]").Any <E>
(lambdaExpr));
}
/// <summary>
/// Verifica si el valor de un campo especifico ya existe.
/// </summary>
/// <param name="fieldName">Nombre del Field</param>
/// <param name="fieldValue">Valor del campo</param>
/// <param name="key">Valor de la llave primaria</param>
/// <returns>True or False</returns>
public bool TrySameValueExist(string fieldName, object fieldValue, string key)
{
// First we define the parameter that we are going to use the clause.
var xParam = Expression.Parameter(typeof(TEntity), typeof(TEntity).Name); //TODO: Maybe it is needed use GetEntitySetName
MemberExpression leftExprFieldCheck =
MemberExpression.Property(xParam, fieldName);
Expression rightExprFieldCheck = Expression.Constant(fieldValue);
BinaryExpression binaryExprFieldCheck =
MemberExpression.Equal(leftExprFieldCheck, rightExprFieldCheck);
MemberExpression leftExprKeyCheck =
MemberExpression.Property(xParam, this._keyProperty);
Expression rightExprKeyCheck = Expression.Constant(key);
BinaryExpression binaryExprKeyCheck =
MemberExpression.NotEqual(leftExprKeyCheck, rightExprKeyCheck);
BinaryExpression finalBinaryExpr =
Expression.And(binaryExprFieldCheck, binaryExprKeyCheck);
//Create Lambda Expression for the selection
Expression <Func <TEntity, bool> > lambdaExpr =
Expression.Lambda <Func <TEntity, bool> >(finalBinaryExpr,
new ParameterExpression[] { xParam });
//Searching ....
return(((IRepository <TEntity>) this).TryEntity(new Specification <TEntity>(lambdaExpr)));
}
/// <summary>
/// Get Entity By Primary Key
/// </summary>
/// <typeparam name="E">Entity Type</typeparam>
/// <param name="Key">Primary Key Value</param>
/// <returns>return entity</returns>
public E SelectByKey(string Key)
{
// First we define the parameter that we are going to use the clause.
var xParam = Expression.Parameter(typeof(E), typeof(E).Name);
MemberExpression leftExpr = MemberExpression.Property(xParam, this._KeyProperty);
Expression rightExpr;
if (leftExpr.Type == typeof(Int32))
{
rightExpr = Expression.Constant(Int32.Parse(Key));
}
else
{
rightExpr = Expression.Constant(Key);
}
BinaryExpression binaryExpr = MemberExpression.Equal(leftExpr, rightExpr);
//Create Lambda Expression for the selection
Expression <Func <E, bool> > lambdaExpr =
Expression.Lambda <Func <E, bool> >(binaryExpr,
new ParameterExpression[] { xParam });
//Searching ....
var resultCollection = (ObjectQuery <E>)_ctx.CreateQuery <E>("[" + this.GetEntitySetName(typeof(E).Name) + "]")
.Where(lambdaExpr);
if (null != resultCollection && resultCollection.Count() > 0)
{
//return valid single result
return(resultCollection.First <E>());
}//end if
return(null);
}
/// <summary>
/// Get Entity By Primary key
/// </summary>
/// <typeparam name="E">Entity Type</typeparam>
/// <param name="key">Primary key Value</param>
/// <returns>return entity</returns>
public TEntity GetByKey(int key)
{
// First we define the parameter that we are going to use the clause.
var xParam = Expression.Parameter(typeof(TEntity), typeof(TEntity).Name);
MemberExpression leftExpr = MemberExpression.Property(xParam, this._KeyProperty);
Expression rightExpr = Expression.Constant(key);
BinaryExpression binaryExpr = MemberExpression.Equal(leftExpr, rightExpr);
//Create Lambda Expression for the selection
Expression <Func <TEntity, bool> > lambdaExpr =
Expression.Lambda <Func <TEntity, bool> >(binaryExpr,
new ParameterExpression[] { xParam });
//Searching ....
IList <TEntity> resultCollection = ((IRepository <TEntity>) this).SelectAll(lambdaExpr);
if (null != resultCollection && resultCollection.Count() > 0)
{
//return valid single result
return(resultCollection.First <TEntity>());
}//end if
return(null);
}
