//--------------------------------------------------------------------------------------------------------------------------------------------------
#region Private methods
//--------------------------------------------------------------------------------------------------------------------------------------------------
private Expression JoinMethod(MethodCallExpression expression)
{
// first argument is another join or method call
if (expression.Arguments[0] is MethodCallExpression)
{
VisitMethodCall((MethodCallExpression)expression.Arguments[0]);
}
var joinFromType = ((LambdaExpression)((UnaryExpression)expression.Arguments[4]).Operand).Parameters[0].Type;
// from type if generic, possbily another join
if (joinFromType.IsGenericType)
{
joinFromType = joinFromType.GenericTypeArguments[1];
}
var joinToType = ((LambdaExpression)((UnaryExpression)expression.Arguments[4]).Operand).Parameters[1].Type;
EntityTableCacheHelper.ToEntityTable(joinFromType);
var joinToTable = EntityTableCacheHelper.ToEntityTable(joinToType);
var primaryJoinColumn = _serverWriter.GetPropertyNameWithIdentifierFromExpression(expression.Arguments[2]);
var secondaryJoinColumn = _serverWriter.GetPropertyNameWithIdentifierFromExpression(expression.Arguments[3]);
_serverWriter.WriteJoin(joinToTable.Name, joinToTable.Identifier, primaryJoinColumn, secondaryJoinColumn);
return(expression);
}
/// <summary>
/// Visits the children of the <see cref="T:System.Linq.Expressions.MethodCallExpression"/>.
/// </summary>
/// <returns>
/// The modified expression, if it or any subexpression was modified; otherwise, returns the original expression.
/// </returns>
/// <param name="node">The expression to visit.</param>
protected override Expression VisitMethodCall(MethodCallExpression node)
{
switch (node.Method.Name)
{
case MethodCall.EndsWith:
case MethodCall.StartsWith:
case MethodCall.Contains:
// LIKE '(%)xyz(%)'
// LIKE IN (x, y, s)
return(LikeInMethod(node));
case MethodCall.IsNullOrEmpty:
// ISNULL(x, '') (!)= ''
if (IsNullMethod(node))
{
return(node);
}
break;
case MethodCall.Join:
return(JoinMethod(node));
case MethodCall.Skip:
_serverWriter.SkipCount = (int)node.Arguments[1].GetValueFromExpression();
return(Visit(node.Arguments[0]));
case MethodCall.Take:
// TOP(..)
_serverWriter.TopCount = (int)node.Arguments[1].GetValueFromExpression();
return(Visit(node.Arguments[0]));
// return node;
case MethodCall.Single:
case MethodCall.First:
case MethodCall.FirstOrDefault:
// TOP(1)
_serverWriter.TopCount = 1;
return(Visit(node.Arguments[node.Arguments.Count - 1]));
case MethodCall.Distinct:
// DISTINCT
_serverWriter.IsDistinct = true;
return(node);
case MethodCall.Count:
case MethodCall.LongCount:
_serverWriter.IsCount = true;
return(Visit(node.Arguments[node.Arguments.Count - 1]));
case MethodCall.OrderBy:
case MethodCall.ThenBy:
case MethodCall.OrderByDescending:
case MethodCall.ThenByDescending:
// ORDER BY ...
_serverWriter.WriteOrder(_serverWriter.GetPropertyNameWithIdentifierFromExpression(node.Arguments[1]), node.Method.Name.Contains("Descending"));
return(Visit(node.Arguments[0]));
case MethodCall.Select:
var type = ((LambdaExpression)((UnaryExpression)node.Arguments[1]).Operand).Body.Type;
EntityTableCacheHelper.ToEntityTable(type);
_serverWriter.SelectType = type;
return(base.VisitMethodCall(node));
}
return(base.VisitMethodCall(node));
}