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  • mysql 语句笔记

    1. 查询某个表中所有非空字段名

    SELECT `COLUMN_NAME`
    FROM `information_schema`.`COLUMNS`
    WHERE
    `IS_NULLABLE` = 'No'
    AND `TABLE_NAME` = 'feed'
    AND `TABLE_SCHEMA` = 'prodb_mgmt'

    2.   查看一个表的所有字段

    describe <表名>

    3.  查看表大小  http://stackoverflow.com/questions/9620198/how-to-get-the-sizes-of-the-tables-of-a-mysql-database 

    SELECT 
        table_name AS `Table`, 
        round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
    FROM information_schema.TABLES 
    WHERE table_schema = "$DB_NAME"
        AND table_name = "$TABLE_NAME";
    

    4. 显示表的建表语句  http://dev.mysql.com/doc/refman/5.7/en/show-create-table.html 

    mysql> show create table serverStatusInfo G;
    *************************** 1. row ***************************
           Table: serverStatusInfo
    Create Table: CREATE TABLE `serverStatusInfo` (
      `date` date NOT NULL,
      `server` varchar(45) NOT NULL,
      `requestsActiveMax` int(10) unsigned default '0',
      `requestTimeMax` int(10) unsigned default '0',
      `requestTimeMean` float default '0',
      `requestTimeStdDev` float default '0',
      PRIMARY KEY  (`date`,`server`)
    ) ENGINE=InnoDB DEFAULT CHARSET=gbk
    1 row in set (0.00 sec)

     4.  删除表中所有数据 Delete / Truncate

    delete from tableName;
    Delete: will delete all rows from your table. Next insert will take next auto increment id.
    
    truncate tableName;
    Truncate: will also delete the rows from your table but it will start from new row with 1.

      

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  • 原文地址:https://www.cnblogs.com/joshuajiang/p/5166654.html
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