MYSQL命令總結(jié)
SHOW TABLES 查看數(shù)據(jù)庫表
use mysql 更改默認(rèn)某個(gè)數(shù)據(jù)庫(如mysql)
DESC 表名 查看表內(nèi)容
SELECT * FROM 表名 查看表信息
FLUSH PRIVILEGES 立即生效
SELECT DATABASE() 顯示當(dāng)前默認(rèn)數(shù)據(jù)庫
DROP DATABASES 數(shù)據(jù)庫表名 刪除某個(gè)表
SHOW CHARACTER SE\C 顯示支持的字符集
SHOW COLLATION 現(xiàn)在字符集
SHOW CURRENT_DATE 顯示日期
SHOW CURRENT_DATETIME() 顯示時(shí)間
SHOW WARNINGS 查看警告
SHOW ENGINES 顯示存儲(chǔ)引擎
SHOW VARIABLES LIKE “%sql_mode%” 模式
SET sql_mode= 設(shè)置模式
例:SET sql_mode=”STRICT_all_tables” 嚴(yán)格模式,
常用的模式: ANSI 只能使用單引號(hào) ; STRICT_ALL_TABLES嚴(yán)格模式,禁止非法數(shù)據(jù)插入; TRADITIONAL 默認(rèn)模式
SHOW GLOBAL VARIALES 全局會(huì)話顯示
SHOW SESSION VARIABLES 當(dāng)前會(huì)話顯示
CREATE DATABASE IF NOT EXISTS aa CHARACTER SET ‘gbk’; 創(chuàng)建aa字符集為gbk
DROP DATABASE IF EXISTS aa; 存在aa則刪除
SHOW CREATE DATABASE aa; 查看創(chuàng)建aa的命令
刪除用戶: DROP USER ‘’@localhost或’root’@localhost
mysqladmin命令用在Shell中:
mysqladmin –uroot –p ping 測試狀態(tài) mysqladmin drop 刪除數(shù)據(jù)庫
mysqladmin debug 日志 mysqladmin create sample 常見sample數(shù)據(jù)庫
mysqladmin extended-status 顯示mysql運(yùn)行狀態(tài) mysqladmin flush-hosts 手動(dòng)刷新日志
mysqladmin flush-privileges 刷新權(quán)限 mysqladmin flush-tables
mysqladmin processlist查看當(dāng)前連接狀態(tài) mysqladmin reload
mysqladmin shutdown 關(guān)閉數(shù)據(jù)庫 mysqladmin start-slave 從服務(wù)器啟動(dòng)
mysqladmin status 顯示狀態(tài) mysqladmin stop-slave 從服務(wù)器關(guān)閉
mysqladmin version 現(xiàn)在版本
mysqladmin status –sleep 3 –count 2 睡3秒,顯示2次
CREATE TABLE [IF NOT EXISTS] tb_name 創(chuàng)建表語法
例:CREATE TABLE users ( ID INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,Name VARCHAR(30) NOT NULL,Age TINYINT UNSIGNED NOT NULL,Gender ENUM('F','M') NOT NULL DEFAULT 'M');
或者:創(chuàng)建表時(shí),指定引擎CREATE TABLE db_name like db_othername; 只創(chuàng)建表結(jié)構(gòu)
SELECT DISTINCT zone FROM zones LIMIT 100; 顯示100行且去除重復(fù)
SELECT zone, COUNT(*) FROM mytb GROUP BY zone; 分組顯示
修改表結(jié)構(gòu):
添加字段:ADD col_name col_ def 添加字段 AFTER col_name在col_name后添加字段,FIRST col_name該字段前加字段
例:
ALTER TABLE user1 ADD Master TINYINT UNSIGNED;
修改字段:CHANGE old_name new_name col_definat
添加索引:例:ALTER TABLE user ADD INDEX (Age);
創(chuàng)建索引: CREATE INDEX 字段名ON 表名(字段名)
例: CREATE INDEX on_name ON juexue(Cname)
刪除字段: DROP col_name
刪除鍵:DROP PRIMARY KEY
給表重命名:ALTER TABLE user RENAME TO qq
插入數(shù)據(jù):INSERT INTO tb_name(字段名) VALUE (‘’,’’,’’)
INSERT INTO tb_name VALUE (‘’,’’,’’)
INSERT INTO tb_name SET 字段名=自定義
刪除數(shù)據(jù):
DELETE FROM tb_name WHERE 條件
TRUNCATE TABLE tb_name 清空數(shù)據(jù)并恢復(fù)初始狀態(tài)
SELECT LAST_INSERT_ID();
ALTER TABLE user AUTO_INCREMENT=2 設(shè)定自動(dòng)增長的ID號(hào)
創(chuàng)建視圖:HELP CREATE VIEW 查看幫助
CREATE VIEW view_name AS SELECT clause WITH CHECK OPTON
刪除視圖:DROP VIEW view_name
子查詢:
例: SELECT Name FROM knight WHERE Age > ( SELECT AVG(Age) FROM knigh WHERE Age IS NOT NULL);
SHOW PROCESSLIST 查看連接狀態(tài)
查看隔離級(jí)別:SHOW VARIABLES LIKE ‘tx%’
START TRANSACTION 啟用事物
例:LOCK TABLES user READ; 啟動(dòng)共享鎖
UNLOCK TABLES 釋放鎖
創(chuàng)建用戶:HELP CRATE USER 查看幫助
CREATE USER user_name@IP IDENTIFIED BY ‘password’
例;CREATE USER jerry@’%’ IDENTIFIED BY ‘REDHAT’
刪除用戶: DROP USER username@IP
授權(quán):GRANT 授權(quán)
格式: GRANT 權(quán)限 ON 表 TO 用戶 [IDENTIFIED BY ‘PASSWORD’]
例:GRANT DROP ON hellodb.* TO ‘jerry’@’%’
例:GRANT ALL PRIVILEGES ON hellodb.* TO ‘jerry’@’%’ 授權(quán)所以權(quán)限
在某個(gè)字段上的權(quán)限:
GRANT SELECT(name) ON db_name TO user@IP
執(zhí)行存儲(chǔ)歷程的權(quán)限:
GRANT EXECUTE ON db_name TO user@IP
SHOW GRANTS FOR ‘root’@’localhost’ 查看root的用戶所擁有的權(quán)限
例:REVOKE SELECT ON hellodb.* FROM ‘jerry’@’%’ 收回select權(quán)限
多表查詢:
連接的類型:
交叉連接(很少用到),例:SELECT * FROM user,user2
內(nèi)連接, 例:SELECT * FROM user,user2 WHERE user.ID=user2.CID表user的字段id和表user2的字段cid連接起來
別名 例:SELECT * FROM user AS A, user2 AS B HWERE A.ID=B.ID
外連接:左外連接、右邊連接、
SLECT k.Name,j.Cname FROM user AS k, LEFT JOIN user2 AS j ON k.CID=J.CID
全外連接,自連接
例:SELECT k1.NAME,k2.Name FROM user AS k1, user2 AS k2 WHERE k1.Age=k2.UID
UNION: 例: SELECT UID AS ID ,Name AS NAME FROM user UNION SELECT CID AD ID, CNAME AS NAME FROM user2
創(chuàng)建表并設(shè)置引擎:
CREATE TABLES users(id INT) ENGINE = InnoDB;
CREATE TABLES users ENGINE = InnoDB;
設(shè)置默認(rèn)引擎:在/etc/my.cnf中加入以下內(nèi)容:default-storage-engine=innodb
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