常用的MySQL语句写法

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。大家不要纠结这些SQL语句包含的业务或是其它问题，本文只是一篇笔记而已。

• 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]

• 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

• 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 B
  SET A.ROLEID = ‘123456’
  WHERE
  A.USERID = B.ID

• 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 B
  SET A.PARENT_DEPART_ID = B.ID
  WHERE
  SUBSTRING(A.ORG_CODE, 1, 6) = B.ORG_CODE

• 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

• 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

• 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
  ) C
  SET A.COMMON_COUNT = B.COMMON_COUNT, A.PROJECT_COUNT = C.PROJECT_COUNT
  WHERE A.USER_ID = B.USER_ID
  AND A.USER_ID = C.USER_ID
  AND DATE_FORMAT(A.RECORD_DATE, ‘%Y-%m-%d’) = ‘2012-06-09’

• 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
  ) B
  SET
  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 END
  WHERE
  A.USER_ID = B.CUST_MGR_ID
  AND DATE_FORMAT(A.RECORD_DATE, ‘%Y-%m-%d’) = ‘2012-06-11’

• 加索引

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

• 删除列

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

• 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;

• 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’;