internal override SqlExpression VisitFunctionCall(SqlFunctionCall fc)
{
// process the arguments
SqlExpression result = base.VisitFunctionCall(fc);
if (result is SqlFunctionCall)
{
SqlFunctionCall resultFunctionCall = (SqlFunctionCall)result;
if (resultFunctionCall.Name == "LEN")
{
SqlExpression expr = resultFunctionCall.Arguments[0];
if (expr.SqlType.IsLargeType && !expr.SqlType.SupportsLength)
{
result = sql.DATALENGTH(expr);
if (expr.SqlType.IsUnicodeType)
{
result = sql.ConvertToInt(sql.Divide(result, sql.ValueFromObject(2, expr.SourceExpression)));
}
}
}
// If the return type of the sql function is not compatible with
// the expected CLR type of the function, inject a conversion. This
// step must be performed AFTER SqlRetyper has run.
Type clrType = resultFunctionCall.SqlType.GetClosestRuntimeType();
bool skipConversion = SqlMethodTransformer.SkipConversionForDateAdd(resultFunctionCall.Name,
resultFunctionCall.ClrType,
clrType);
if ((resultFunctionCall.ClrType != clrType) && !skipConversion)
{
result = sql.ConvertTo(resultFunctionCall.ClrType, resultFunctionCall);
}
}
return(result);
}