单项选择题
A.UNIQUEB.DISTINCTC.ONLYD.SINGLE
A.SELECT *FROM table GROUP columnB.SELECT *FROM table BY columnC.SELECT *FROM table GROUP BY columnD.SELECT *FROM table BY GROUP column
A.SELECT *FROM table WHERE column =value HAVING conditionB.SELECT *FROM table HAVING column =value GROUP BY conditionC.SELECT *FROM table GROUP BY column HAVING conditionD.SELECT *FROM table GROUP BY column WHERE condition HAVING value