public virtual CommandDefinition ToCountStatement(CountStatement statement, CommandFlags flags)
{
var sql = new StringBuilder("SELECT COUNT(");
if (statement.IsDistinct)
{
sql.Append(" DISTINCT ");
}
sql.Append(statement.Columns.Count == 1 ? statement.Columns[0] : "*");
sql.Append(")\n FROM ");
sql.Append(statement.TableName);
if (statement.WhereExpression.Length > 0)
{
sql.Append("\n WHERE ");
sql.Append(statement.WhereExpression);
}
if (statement.GroupByExpression.Length > 0)
{
sql.Append("\n GROUP BY ");
sql.Append(statement.GroupByExpression);
}
if (statement.HavingExpression.Length > 0)
{
sql.Append("\n HAVING ");
sql.Append(statement.HavingExpression);
}
return(new CommandDefinition(sql.ToString(), statement.Parameters, flags: flags));
}
private void AddResultOperator(ResultOperatorBase resultOperator, IFieldMapping fields)
{
switch (resultOperator)
{
case ISelectableOperator selectable:
CurrentStatement = selectable.ModifyStatement(CurrentStatement, _session);
break;
case TakeResultOperator take:
CurrentStatement.Limit = (int)take.Count.Value();
break;
case SkipResultOperator skip:
CurrentStatement.Offset = (int)skip.Count.Value();
break;
case AnyResultOperator _:
CurrentStatement.ToAny();
break;
case CountResultOperator _:
if (CurrentStatement.IsDistinct)
{
CurrentStatement.ConvertToCommonTableExpression(_session);
CurrentStatement = new CountStatement <int>(CurrentStatement);
}
else
{
CurrentStatement.ToCount <int>();
}
break;
case LongCountResultOperator _:
if (CurrentStatement.IsDistinct)
{
CurrentStatement.ConvertToCommonTableExpression(_session);
CurrentStatement = new CountStatement <long>(CurrentStatement);
}
else
{
CurrentStatement.ToCount <long>();
}
break;
case FirstResultOperator first:
CurrentStatement.Limit = 1;
CurrentStatement.SingleValue = true;
CurrentStatement.ReturnDefaultWhenEmpty = first.ReturnDefaultWhenEmpty;
CurrentStatement.CanBeMultiples = true;
break;
case SingleResultOperator single:
CurrentStatement.Limit = 2;
CurrentStatement.SingleValue = true;
CurrentStatement.ReturnDefaultWhenEmpty = single.ReturnDefaultWhenEmpty;
CurrentStatement.CanBeMultiples = false;
break;
case DistinctResultOperator _:
CurrentStatement.IsDistinct = true;
CurrentStatement.ApplySqlOperator("distinct");
break;
case AverageResultOperator _:
CurrentStatement.ApplyAggregateOperator("AVG");
break;
case SumResultOperator _:
CurrentStatement.ApplyAggregateOperator("SUM");
break;
case MinResultOperator _:
CurrentStatement.ApplyAggregateOperator("MIN");
break;
case MaxResultOperator _:
CurrentStatement.ApplyAggregateOperator("MAX");
break;
case ToJsonArrayResultOperator _:
CurrentStatement.ToJsonSelector();
break;
case LastResultOperator _:
throw new InvalidOperationException("Marten does not support Last() or LastOrDefault() queries. Please reverse the ordering and use First()/FirstOrDefault() instead");
case IncludeResultOperator includeOp:
var include = includeOp.BuildInclude(_session, fields);
_provider.AllIncludes.Add(include);
break;
default:
throw new NotSupportedException("Don't yet know how to deal with " + resultOperator);
}
}
