oracle 中随机取一条记录的两种方法
V_COUNT INT:=0;
V_NUM INT :=0;
1:TBL_MYTABLE 表中要有一个值连续且唯一的列FID
BEGIN
SELECT COUNT(*)
INTO V_COUNT
FROM TBL_MYTABLE;
SELECT TRUNC(DBMS_RADOM.VALUE(1,V_COUNT+1)) INTO V_NUM FROM DUAL;
SELECT *
FROM TBL_MYTABLE T
WHERE T.FID=V_NUM;
EXCEPTION
WHEN NO_DATA_FOUND THEN
NULL;
END;
2:第二种方法很简便
BEGIN
SELECT *
FROM
(
SELECT *
FROM TBL_MYTABLE T
ORDER BY DBMS_RADOM.VALUE();
)
WHERE ROWNUM<2;
EXCEPTION
WHEN NO_DATA_FOUND THEN
NULL;
END;
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