MySQL的SQL语句写法，除了那些基本的之外，还有一些也算比较常用的，这里记录下来，以便以后查找。

好记性不如烂笔头，这话说的太有道理了，一段时间不写它，还真容易忘记，本文只是一篇笔记而已。

1.将数据从T1表导入到T2表

INSERT INTO T2 (C1,C2) SELECT C1,C2 FROM T1 [WHERE C1 = XX AND C2 = XX ORDER BY C1]

2.使用T2表的NAME来更新T1表的NAME

UPDATE T1 AS A, T2 AS B SET A.NAME = B.NAME WHERE A.TID = B.ID

3.两表的关联更新

UPDATE T_ROLE_USER AS A, (    SELECT        ID    FROM        T_USER    WHERE        DEPARTID IN (            SELECT                ID            FROM                T_DEPART            WHERE                LENGTH(ORG_CODE) = 9        )) AS BSET A.ROLEID = '123456'WHERE    A.USERID = B.ID

4.自己和自己关联更新

UPDATE T_DEPART AS A, (    SELECT        ID,        SUBSTRING(ORG_CODE, 1, 6) ORG_CODE    FROM        T_DEPART    WHERE        LENGTH(ORG_CODE) = 8    AND PARENT_DEPART_ID IS NOT NULL) AS BSET A.PARENT_DEPART_ID = B.IDWHERE    SUBSTRING(A.ORG_CODE, 1, 6) = B.ORG_CODE

5.两表关联删除，将删除两表中有关联ID并且T2表NAME为空的两表记录

DELETE A,B FROM T1 AS A LEFT JOIN T2 AS B ON A.TID = B.ID WHERE B.NAME IS NULL

6.将统计结果插入到表

INSERT INTO SE_STAT_ORG (    RECORD_DATE,    ORG_ID,    ORG_NAME,    SIGN_CONT_COUNT,    SIGN_ARRI_CONT_COUNT,    SIGN_CONT_MONEY,    SIGN_ARRI_CONT_MONEY,    TOTAL_ARRI_CONT_COUNT,    TOTAL_ARRI_MONEY,    PUBLISH_TOTAL_COUNT,    PROJECT_COUNT) SELECT    *FROM    (        SELECT            '2012-06-09' RECORD_DATE,            PARENT_ORG_ID,            PARENT_ORG_NAME,            SUM(SIGN_CONT_COUNT) SIGN_CONT_COUNT,            SUM(SIGN_ARRI_CONT_COUNT) SIGN_ARRI_CONT_COUNT,            SUM(SIGN_CONT_MONEY) SIGN_CONT_MONEY,            SUM(SIGN_ARRI_CONT_MONEY) SIGN_ARRI_CONT_MONEY,            SUM(TOTAL_ARRI_CONT_COUNT) TOTAL_ARRI_CONT_COUNT,            SUM(TOTAL_ARRI_MONEY) TOTAL_ARRI_MONEY,            SUM(PUBLISH_TOTAL_COUNT) PUBLISH_TOTAL_COUNT,            SUM(PROJECT_COUNT) PROJECT_COUNT,        FROM SE_STAT_USER        WHERE DATE_FORMAT(RECORD_DATE, '%Y-%m-%d') = '2012-06-09'        GROUP BY PARENT_ORG_ID    ) M

7. 三表关联更新

UPDATE SE_STAT_USER A, (    SELECT        USER_ID,        SUM(INVEST_ORG_COUNT + FINANCIAL_ORG_COUNT + INTERMEDIARY_ORG_COUNT + ENTERPRISE_COUNT) AS COMMON_COUNT    FROM SE_STAT_USER    WHERE DATE_FORMAT(RECORD_DATE, '%Y-%m-%d') = '2012-06-09'    GROUP BY USER_ID) B, (    SELECT        USER_ID,        SUM(ESTABLISH_COUNT + STOCK_COUNT + MERGER_COUNT + ACHIEVE_COUNT) AS PROJECT_COUNT    FROM SE_STAT_USER    WHERE DATE_FORMAT(RECORD_DATE, '%Y-%m-%d') = '2012-06-09'    GROUP BY USER_ID) CSET A.COMMON_COUNT = B.COMMON_COUNT, A.PROJECT_COUNT = C.PROJECT_COUNTWHERE A.USER_ID = B.USER_IDAND A.USER_ID = C.USER_IDAND DATE_FORMAT(A.RECORD_DATE, '%Y-%m-%d') = '2012-06-09'

8.带条件的关联更新

UPDATE SE_STAT_USER A, (    SELECT        P.CHANNEL,        COUNT(P.CONT_ID) AS CONT_COUNT,        C.CUST_MGR_ID    FROM        (            SELECT                CHANNEL,                CONT_ID            FROM SK_PROJECT            WHERE PROJECT_STATUS = 6            AND DATE_FORMAT(AUDIT_TIME, '%Y-%m-%d') = '2012-06-11'        ) p    INNER JOIN SE_ConTRACT C ON P.CONT_ID = C.CONT_ID    GROUP BY P.CHANNEL, C.CUST_MGR_ID) BSET    A.STOCK_COUNT = CASE WHEN B.CHANNEL = 2 THEN B.CONT_COUNT ELSE 0 END,    A.ESTABLISH_COUNT = CASE WHEN B.CHANNEL = 3 THEN B.CONT_COUNT ELSE 0 END,    A.ACHIEVE_COUNT = CASE WHEN B.CHANNEL = 4 THEN B.CONT_COUNT ELSE 0 END,     A.BRAND_COUNT = CASE WHEN B.CHANNEL = 5 THEN B.CONT_COUNT ELSE 0 END,    A.MERGER_COUNT = CASE WHEN B.CHANNEL = 6 THEN B.CONT_COUNT ELSE 0 ENDWHERE    A.USER_ID = B.CUST_MGR_IDAND DATE_FORMAT(A.RECORD_DATE, '%Y-%m-%d') = '2012-06-11'

9. 加索引

ALTER TABLE PROJECT ADD INDEX INDEX_USER_ID (USER_ID),        ADD INDEX INDEX_PROJECT_STATUS (PROJECT_STATUS);

10.删除列

ALTER TABLE PROJECT DROP COLUMN PROJECT_STATUS,        DROP COLUMN EXPECT_RETURN,DROP COLUMN CURRENCY;

11.增加列

ALTER TABLE PROJECT         ADD COLUMN DICT_ID INT DEFAULT NULL COMMENT 'xxx' AFTER PROJECT_SITE,        ADD COLUMN INTRODUCE TEXT DEFAULT NULL COMMENT 'xx' AFTER DICT_ID,        ADD COLUMN STAGE INT DEFAULT NULL COMMENT 'xx' AFTER ID,        ADD COLUMN ATTACH_URI VARCHAR(8) DEFAULT NULL COMMENT 'xxx' AFTER INTRODUCE;

12.修改列
一般用MODIFY修改数据类型，CHANGE修改列名。

ALTER TABLE PROJECT CHANGE DICT_ID DICT_ID1 INT NOT NULL,        MODIFY PROJECT_STATUS TINYINT NOT NULL COMMENT 'xxx';

不同数据库此属性不一样，MYSQL 与ORACLE,MS SQL SERVER不一样，见具体文档

w3school.cn/sql/sql_autoincrement.asp

自增

ALTER TABLE persons AUTO_INCREMENT=1;