public TResult Execute <TResult>(System.Linq.Expressions.Expression expression)
{
SAPTable <TResult> table = (SAPTable <TResult>) this.CreateQuery <TResult>(expression);
if (table._count && (typeof(TResult) == typeof(int)))
{
return((TResult)table.GetResultsCount());
}
if (typeof(TResult) == typeof(TEntity))
{
return((TResult)table.GetResultsSingle());
}
if (typeof(TResult) != typeof(IEnumerable <TEntity>))
{
throw new NotSupportedException("The given expression cannot be evaluated and executed");
}
return((TResult)table.GetResults());
}
public IQueryable <TElement> CreateQuery <TElement>(System.Linq.Expressions.Expression expression)
{
SAPTable <TElement> table = new SAPTable <TElement>(this.Connection, this.Log)
{
_query = this._query,
_skip = this._skip,
_take = this._take,
_orderBy = this._orderBy,
_projection = this._projection,
_properties = this._properties,
_originalType = this._originalType,
_useMultibyteExtraction = this._useMultibyteExtraction,
_SAPDataContext = this._SAPDataContext,
_count = this._count,
_first = this._first,
_firstOrDefault = this._firstOrDefault,
_last = this._last,
_lastOrDefault = this._lastOrDefault
};
MethodCallExpression expression2 = expression as MethodCallExpression;
if (expression2 == null)
{
throw new NotSupportedException(expression.ToString());
}
switch (expression2.Method.Name)
{
case "Where":
table.BuildQuery(((UnaryExpression)expression2.Arguments[1]).Operand as LambdaExpression);
return(table);
case "Select":
table.BuildProjection(((UnaryExpression)expression2.Arguments[1]).Operand as LambdaExpression);
return(table);
case "Take":
table._take = Convert.ToInt32(((ConstantExpression)expression2.Arguments[1]).Value);
return(table);
case "Skip":
table._skip = Convert.ToInt32(((ConstantExpression)expression2.Arguments[1]).Value);
return(table);
case "OrderBy":
table.BuildOrderBy(((UnaryExpression)expression2.Arguments[1]).Operand as LambdaExpression, false);
return(table);
case "OrderByDescending":
table.BuildOrderBy(((UnaryExpression)expression2.Arguments[1]).Operand as LambdaExpression, true);
return(table);
case "ThenBy":
table.BuildOrderBy(((UnaryExpression)expression2.Arguments[1]).Operand as LambdaExpression, false);
return(table);
case "ThenByDescending":
table.BuildOrderBy(((UnaryExpression)expression2.Arguments[1]).Operand as LambdaExpression, true);
return(table);
case "Count":
table._count = true;
return(table);
case "First":
table._first = true;
return(table);
case "FirstOrDefault":
table._firstOrDefault = true;
return(table);
case "Last":
table._last = true;
return(table);
case "LastOrDefault":
table._lastOrDefault = true;
return(table);
}
throw new NotSupportedException("Unsupported method detected: " + expression2.Method.Name);
}
