vectorJ的博客

生成修改语句SELECT CONCAT('ALTER TABLE ', table_name, ' MODIFY ', column_name, ' ', DATA_TYPE, '(', CHARACTER_MAXIMUM_LENGTH, ') CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci', (CASE WHEN IS_NULLABLE = 'NO' THEN ' NOT NULL' ELSE '' END), ';') from informat

有主键（systemid）的情况下,按创建人（created_by）进行分组查询，对分组后数量大于1（HAVING COUNT(*) > 1） 的数据进行删除。DELETE FROM tablename WHEREsystemid IN (SELECT systemid FROM (SELECT created_by,min(systemid) systemid FROM tablenameGROUP BY created_byHAVING COUNT(*) > 1) AS a)

SELECT * FROM dba_objects obj WHERE obj.OWNER=‘用户名’ and obj.OBJECT_TYPE=‘TABLE’ AND obj.CREATED BETWEEN ‘开始时间’ AND ‘结束时间’ ORDER BY obj.CREATED DESC;