如果一張表中存在數據重複,如何快速高效去重?
通過rowid去重效率最高,demo如下:
EMPLOYEE_ID 爲去重後唯一關鍵字
DELETE FROM SCOTT.F_EMPLOYEE
WHERE ROWID NOT IN (SELECT MIN(ROWID)
FROM ISCOTT.F_EMPLOYEE
group by EMPLOYEE_ID);
如果一張表中存在數據重複,如何快速高效去重?
通過rowid去重效率最高,demo如下:
EMPLOYEE_ID 爲去重後唯一關鍵字
DELETE FROM SCOTT.F_EMPLOYEE
WHERE ROWID NOT IN (SELECT MIN(ROWID)
FROM ISCOTT.F_EMPLOYEE
group by EMPLOYEE_ID);