Oracle 显示数据库名和表名 Oracle 查看表名: select table_name from user_tables; select table_name from dba_tables; select * from all_all_tables; Oracle 查看数据库名: select * from v$database; MySQL 显示数据库名和表名 MySQL 查看表名: show tables; MySQL 查看数据库名: show databases;
oracle查看表名 select table_name from user_tables; select table_name from dba_tables; select * from all_all_tables oracle查看数据库名 select * from v$database; mysql查看表名: show tables: mysql查看数据库名: show databases;
1. 视图 创建视图 create view 视图名字 as 查询sql语句; drop view 视图名字; alter view 视图名字 as 查询sql语句; 2. 触发器 1. 插入事件触发器 INSERT INTO order_table(gid,much) VALUES(1,3); -- update goods set num = num -3 where id =1; CREATE TRIGGER tg1 AFTER INSERT on order_table for EACH
1.查询sjcenter数据库里开头为sj_demo和sj_onlyinv的所有表的总条数 select sum(table_rows) from (select table_name,table_rows from tables where TABLE_SCHEMA = 'sjcenter' order by table_rows desc) as b where b.table_name like 'sj_demo%' or b.table_name like 'sj_onlyinv'
SELECT ii.`COLUMN_NAME` FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS ii WHERE ii.`CONSTRAINT_SCHEMA`='xius' AND ii.`TABLE_NAME`='comment_user' AND ii.`REFERENCED_COLUMN_NAME` != 'null'; xius: 数据库名 comment_user: 表名
查询数据库中所有表名select table_name from information_schema.tables where table_schema='数据库名' and table_type='base table';查询指定数据库中指定表的所有字段名column_nameselect column_name from information_schema.columns where table_schema='数据库名' and table_name='表名'; #查看分布式系统中不同
1.创建一个mysql用户并设置密码create user 'MySql用户名'@'localhost' identified by '密码';2.限制账户资源grant usage on *.* to 'MySql用户名'@'localhost' identified by '密码' WITHMAX_QUERIES_PER_HOUR 0 MAX_CONNECTIONS_PER_HOUR 0 MAX_UPDATES_PER_HOUR 0MAX_USER_CONNECTIONS 0;3.创建数据库