private void VisitCallHelper(string functionName, ODataCallExpression node)
{
this.Write(functionName).Write("(");
for (var i = 0; i < node.Arguments.Count; ++i)
{
this.Write(", ", @if: i > 0);
this.Visit(node.Arguments[i]);
}
this.Write(")");
}
protected override void VisitCall(ODataCallExpression node)
{
// reference for different function syntax http://users.atw.hu/sqlnut/sqlnut2-chp-4-sect-4.html
switch (node.Function)
{
case ODataFunction.Cast:
this.Write("CAST(").Write(node.Arguments[0]);
var toType = ((Type)((ODataConstantExpression)node.Arguments[1]).Value).ToODataExpressionType();
this.Write(" AS ").Write(this.syntaxProvider.GetSqlTypeName(toType)).Write(")");
break;
case ODataFunction.Ceiling:
this.VisitCallHelper(this.syntaxProvider.UseAbbreviatedCeilingFunction ? "CEIL" : "CEILING", node);
break;
case ODataFunction.Concat:
this.Write("(").Write(node.Arguments[0])
.Write(" + ")
.Write(node.Arguments[1]).Write(")");
break;
case ODataFunction.Second:
case ODataFunction.Minute:
case ODataFunction.Hour:
case ODataFunction.Day:
case ODataFunction.Month:
case ODataFunction.Year:
this.syntaxProvider.RenderDatePartFunctionCall(node.Function, s => this.Write(s), () => this.Write(node.Arguments[0]));
break;
case ODataFunction.EndsWith:
// endswith => (INDEXOF(needle, haystack) = LEN(haystack) - LEN(needle)) OR LEN(needle) = 0
var needleLengthExpression = ODataExpression.Call(ODataFunction.Length, new[] { node.Arguments[1] });
var endsWithExpression = ODataExpression.BinaryOp(
ODataExpression.BinaryOp(
ODataExpression.Call(ODataFunction.IndexOf, node.Arguments),
ODataBinaryOp.Equal,
ODataExpression.BinaryOp(
ODataExpression.Call(ODataFunction.Length, new[] { node.Arguments[0] }),
ODataBinaryOp.Subtract,
needleLengthExpression
)
),
ODataBinaryOp.Or,
ODataExpression.BinaryOp(
needleLengthExpression,
ODataBinaryOp.Equal,
ODataExpression.Constant(0)
)
);
this.Visit(endsWithExpression);
break;
case ODataFunction.StartsWith:
// startswith => INDEXOF(needle, haystack) = 0
var startsWithExpression = ODataExpression.BinaryOp(
ODataExpression.Call(ODataFunction.IndexOf, node.Arguments),
ODataBinaryOp.Equal,
ODataExpression.Constant(0)
);
this.Visit(startsWithExpression);
break;
case ODataFunction.SubstringOf:
// substringof => INDEXOF(needle, haystack) >= 0
var substringOfExpression = ODataExpression.BinaryOp(
ODataExpression.Call(ODataFunction.IndexOf, node.Arguments.Reverse()),
ODataBinaryOp.GreaterThanOrEqual,
ODataExpression.Constant(0)
);
this.Visit(substringOfExpression);
break;
case ODataFunction.IndexOf:
this.syntaxProvider.RenderIndexOfFunctionCall(s => this.Write(s), renderNeedleArgument: () => this.Write(node.Arguments[1]), renderHaystackArgument: () => this.Write(node.Arguments[0]));
break;
case ODataFunction.Floor:
this.VisitCallHelper("FLOOR", node);
break;
case ODataFunction.Length:
this.VisitCallHelper(this.syntaxProvider.StringLengthFunctionName, node);
break;
case ODataFunction.Replace:
this.VisitCallHelper("REPLACE", node);
break;
case ODataFunction.Round:
this.syntaxProvider.RenderRoundFunctionCall(s => this.Write(s), () => this.Write(node.Arguments[0]));
break;
case ODataFunction.Substring:
this.syntaxProvider.RenderSubstringFunctionCall(s => this.Write(s), () => this.Write(node.Arguments[0]), () => this.Write(node.Arguments[1]), node.Arguments.Count > 2 ? new Action(() => this.Write(node.Arguments[2])) : null);
break;
case ODataFunction.ToLower:
this.VisitCallHelper("LOWER", node);
break;
case ODataFunction.ToUpper:
this.VisitCallHelper("UPPER", node);
break;
case ODataFunction.Trim:
if (this.syntaxProvider.HasTwoSidedTrim)
{
this.VisitCallHelper("TRIM", node);
}
else
{
// call both LTRIM and RTRIM
this.VisitCallHelper("LTRIM(RTRIM", node);
this.Write(")");
}
break;
case ODataFunction.IsOf:
throw new NotSupportedException(node.Function.ToString());
}
}
