private void HandleSum(FunctionCall functionCall)
{
//Mark query as aggregate, all selects must be either aggregate or in group by
var parameters = functionCall.Parameters;
if (parameters.Count != 1)
{
throw new NotSupportedException("Sum can only take a single parameter");
}
_inAggregateFunction = true;
foreach (var parameter in parameters)
{
parameter.Accept(this);
}
_inAggregateFunction = false;
var argumentAccessExpression = PopStack();
var callMethodExpression = AggregationUtils.CallSum(argumentAccessExpression, this._previousStage);
AddExpressionToStack(callMethodExpression);
var lastName = PopNameStack();
AddNameToStack($"sum({lastName})");
}
private void HandleCount(FunctionCall functionCall)
{
var parameters = functionCall.Parameters;
if (functionCall.Wildcard)
{
AddExpressionToStack(AggregationUtils.CallCount(_previousStage));
AddNameToStack($"count(*)");
}
else
{
throw new SqlErrorException("Count only works with '*' right now.");
}
}
public override void VisitFunctionCall(FunctionCall functionCall)
{
//throw new Exception("FIX FUNCTION CALL WILDCARD PARAMETER");
var parameterListBuilder = ImmutableList.CreateBuilder <Expression>();
foreach (var p in functionCall.Parameters)
{
p.Accept(this);
var parameterExpression = PopStack();
parameterListBuilder.Add(parameterExpression);
}
Parameters = parameterListBuilder.ToImmutable();
var functionName = functionCall.FunctionName.ToLower();
switch (functionName)
{
case "count":
FunctionName = functionName;
OutType = typeof(long);
AddNameToStack($"count(*)");
break;
case "sum":
FunctionName = functionName;
var lastName = PopNameStack();
if (Parameters.Count != 1)
{
throw new SqlErrorException($"Sum can only be called with a single parameter");
}
var parameter = Parameters[0];
OutType = AggregationUtils.GetSumOutputType(parameter.Type);
AddNameToStack($"sum({lastName})");
break;
default:
throw new NotSupportedException(functionCall.FunctionName);
}
}