public IAggregateFunctionExecutor GetAggregateFunctionExecutor(ExecuteAggregateFunctionStage executeAggregateFunctionStage)
{
var t = typeof(DefaultAggregateFunctionExecutor <,>).MakeGenericType(executeAggregateFunctionStage.InType, executeAggregateFunctionStage.OutType);
var executor = (IAggregateFunctionExecutor)Activator.CreateInstance(t);
return(executor);
}
public async ValueTask <IQueryable> Visit(ExecuteAggregateFunctionStage executeAggregateFunctionStage)
{
Debug.Assert(queryable != null);
var aggregateFunctionExecutor = _aggregateFunctionExecutorFactory.GetAggregateFunctionExecutor(executeAggregateFunctionStage);
var selectResult = await aggregateFunctionExecutor.Execute(queryable, executeAggregateFunctionStage);
columns = selectResult.Columns;
return(selectResult.Queryable);
}
private OutType HandleSumFunction(IQueryable <Entity> queryable, ExecuteAggregateFunctionStage executeAggregateFunctionStage)
{
Debug.Assert(executeAggregateFunctionStage.Parameters.Count == 1);
var parameter = executeAggregateFunctionStage.Parameters[0];
if (typeof(OutType) == typeof(decimal?))
{
return(queryable.Sum(GetParameterLambda <decimal?>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(decimal))
{
return(queryable.Sum(GetParameterLambda <decimal>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(double?))
{
return(queryable.Sum(GetParameterLambda <double?>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(double))
{
return(queryable.Sum(GetParameterLambda <double>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(float?))
{
return(queryable.Sum(GetParameterLambda <float?>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(float))
{
return(queryable.Sum(GetParameterLambda <float>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(int?))
{
return(queryable.Sum(GetParameterLambda <int?>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(int))
{
return(queryable.Sum(GetParameterLambda <int>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(long?))
{
return(queryable.Sum(GetParameterLambda <long?>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(long))
{
return(queryable.Sum(GetParameterLambda <long>(executeAggregateFunctionStage.ParameterExpression, parameter)).Cast <OutType>());
}
if (typeof(OutType) == typeof(short))
{
return(((short)queryable.Sum(GetParameterLambda <int>(executeAggregateFunctionStage.ParameterExpression, parameter))).Cast <OutType>());
}
throw new SqlErrorException($"Type ${typeof(OutType).Name} is not supported for sum operations");
}
public override ValueTask <OutType> ExecuteAggregateFunction(
IQueryable <Entity> queryable,
ExecuteAggregateFunctionStage executeAggregateFunctionStage)
{
switch (executeAggregateFunctionStage.FunctionName)
{
case "count":
return(new ValueTask <OutType>(queryable.LongCount().Cast <OutType>()));
case "sum":
return(new ValueTask <OutType>(HandleSumFunction(queryable, executeAggregateFunctionStage)));
default:
throw new NotImplementedException($"The function {executeAggregateFunctionStage.FunctionName} is not yet implemented.");
}
}
public async ValueTask <SelectResult> Execute(IQueryable queryable, ExecuteAggregateFunctionStage executeAggregateFunctionStage)
{
var result = await ExecuteAggregateFunction((IQueryable <Entity>) queryable, executeAggregateFunctionStage);
var outType = typeof(OutType);
var anonType = AnonType.GetAnonType(outType);
var getDelegate = AnonTypeUtils.GetDelegates(anonType)[0];
var columnMetadata = new ColumnMetadata(executeAggregateFunctionStage.ColumnName, result.GetType(), getDelegate);
List <AnonType <OutType> > output = new List <AnonType <OutType> >()
{
new AnonType <OutType>()
{
P0 = result
}
};
return(new SelectResult(output.AsQueryable(), ImmutableList.Create(columnMetadata)));
}
public abstract ValueTask <OutType> ExecuteAggregateFunction(IQueryable <Entity> queryable, ExecuteAggregateFunctionStage executeAggregateFunctionStage);
