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#ifndef QUERYEXECUTORWRAPDISTINCTRESULTS_H
#define QUERYEXECUTORWRAPDISTINCTRESULTS_H
#include "queryexecutorstep.h"
/**
* @brief The QueryExecutorWrapDistinctResults class
*
* This step is necessary for DISTINCT and GROUP BY selects,
* because result columns are always limited by substr() function,
* which makes INT and TEXT types of data to be the same, which is false.
* For those cases, we need to put DISTINCT/GROUP BY into subselect,
* so it works on original result columns, then get the substr() from them.
*
* Processed query is stored in QueryExecutor::Context::processedQuery.
*/
class QueryExecutorWrapDistinctResults : public QueryExecutorStep
{
Q_OBJECT
public:
bool exec();
private:
/**
* @brief Wraps single SELECT statement.
* @param select SELECT to wrap.
*
* Puts given \p select as subselect of a new SELECT.
*/
void wrapSelect(SqliteSelect* select);
};
#endif // QUERYEXECUTORWRAPDISTINCTRESULTS_H
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