bool CanBeCompiled(Expression expr)
{
return null == expr.Find(ex =>
{
if (IsServerSideOnly(ex))
return true;
switch (ex.NodeType)
{
case ExpressionType.Parameter :
return ex != ParametersParam;
case ExpressionType.MemberAccess :
{
var attr = GetFunctionAttribute(((MemberExpression)ex).Member);
return attr != null && attr.ServerSideOnly;
}
case ExpressionType.Call :
{
var attr = GetFunctionAttribute(((MethodCallExpression)ex).Method);
return attr != null && attr.ServerSideOnly;
}
}
return false;
});
}
bool CanBeConstant(Expression expr)
{
return null == expr.Find(ex =>
{
if (ex is BinaryExpression || ex is UnaryExpression || ex.NodeType == ExpressionType.Convert)
return false;
switch (ex.NodeType)
{
case ExpressionType.Constant:
{
var c = (ConstantExpression)ex;
if (c.Value == null || ExpressionHelper.IsConstant(ex.Type))
return false;
break;
}
case ExpressionType.MemberAccess:
{
var ma = (MemberExpression)ex;
if (ExpressionHelper.IsConstant(ma.Member.DeclaringType) || TypeHelper.IsNullableValueMember(ma.Member))
return false;
break;
}
case ExpressionType.Call:
{
var mc = (MethodCallExpression)ex;
if (ExpressionHelper.IsConstant(mc.Method.DeclaringType) || mc.Method.DeclaringType == typeof(object))
return false;
var attr = GetFunctionAttribute(mc.Method);
if (attr != null && !attr.ServerSideOnly)
return false;
break;
}
}
return true;
});
}
bool CanBeTranslatedToSql(IParseContext context, Expression expr, bool canBeCompiled)
{
return null == expr.Find(pi =>
{
switch (pi.NodeType)
{
case ExpressionType.MemberAccess:
{
var ma = (MemberExpression)pi;
var l = ConvertMember(ma.Member);
if (l != null)
return !CanBeTranslatedToSql(context, l.Body.Unwrap(), canBeCompiled);
var attr = GetFunctionAttribute(ma.Member);
if (attr == null && !TypeHelper.IsNullableValueMember(ma.Member))
goto case ExpressionType.Parameter;
break;
}
case ExpressionType.Parameter:
{
if (canBeCompiled && GetContext(context, pi) == null)
return !CanBeCompiled(pi);
break;
}
case ExpressionType.Call:
{
var e = pi as MethodCallExpression;
if (e.Method.DeclaringType != typeof(Enumerable))
{
var cm = ConvertMethod(e);
if (cm != null)
return !CanBeTranslatedToSql(context, cm, canBeCompiled);
var attr = GetFunctionAttribute(e.Method);
if (attr == null && canBeCompiled)
return !CanBeCompiled(pi);
}
break;
}
case ExpressionType.New: return true;
}
return false;
});
}
bool CheckSubQueryForWhere(IParseContext context, Expression expression, out bool makeHaving)
{
//var checkParameter = true; //context.IsExpression(expression, 0, RequestFor.ScalarExpression);
var makeSubQuery = false;
var isHaving = false;
var isWhere = false;
expression.Find(expr =>
{
if (IsSubQuery(context, expr))
return isWhere = true;
var stopWalking = false;
switch (expr.NodeType)
{
case ExpressionType.MemberAccess:
{
var ma = (MemberExpression)expr;
if (TypeHelper.IsNullableValueMember(ma.Member))
break;
if (ConvertMember(ma.Member) == null)
{
var ctx = GetContext(context, expr);
if (ctx != null)
{
if (ctx.IsExpression(expr, 0, RequestFor.Expression))
makeSubQuery = true;
stopWalking = true;
}
}
isWhere = true;
break;
}
case ExpressionType.Call:
{
var e = (MethodCallExpression)expr;
if (e.Method.DeclaringType == typeof(Enumerable) && e.Method.Name != "Contains")
return isHaving = true;
isWhere = true;
break;
}
case ExpressionType.Parameter:
{
var ctx = GetContext(context, expr);
if (ctx != null)
{
if (ctx.IsExpression(expr, 0, RequestFor.Expression))
makeSubQuery = true;
stopWalking = true;
}
isWhere = true;
break;
}
}
return stopWalking;
});
makeHaving = isHaving && !isWhere;
return makeSubQuery || isHaving && isWhere;
}
static Expression FindExpression(Expression expr)
{
var ret = expr.Find(pi =>
{
switch (pi.NodeType)
{
case ExpressionType.Convert :
{
var e = (UnaryExpression)expr;
return
e.Operand.NodeType == ExpressionType.ArrayIndex &&
((BinaryExpression)e.Operand).Left == ParametersParam;
}
case ExpressionType.MemberAccess :
case ExpressionType.New :
return true;
}
return false;
});
if (ret == null)
throw new NotImplementedException();
return ret;
}
