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mysql 基本操作

mysql 基本操作

作者: 逍遥_yjz | 来源:发表于2021-05-13 16:02 被阅读0次

    Python中创建GUID / UUID,序列号

    >>> import uuid
    >>> uuid.uuid4()
    UUID('bd65600d-8669-4903-8a14-af88203add38')
    >>> str(uuid.uuid4())
    'f50ec0b7-f960-400d-91f0-c42a6d44e3d0'
    >>> uuid.uuid4().hex
    '9fe2c4e93f654fdbb24c02b15259716c'
    

    1. 建表

    CREATE TABLE IF NOT EXISTS `waterLevel`(
       `id` INT UNSIGNED AUTO_INCREMENT,
       `baseline_time` datatime,
       `pre_level` VARCHAR(40) NOT NULL,
       PRIMARY KEY ( `id` )
    )ENGINE=InnoDB DEFAULT CHARSET=utf8;
    
    CREATE TABLE IF NOT EXISTS `tips`(
       `id` INT UNSIGNED AUTO_INCREMENT,
       `total_bill` int,
       `tip` int,
       `sex` VARCHAR(40) NOT NULL,
       `smoker` VARCHAR(40) NOT NULL,
       `day` VARCHAR(40) NOT NULL,
       `time` VARCHAR(40) NOT NULL,
       `size` VARCHAR(40) NOT NULL,
       PRIMARY KEY ( `id` )
    )ENGINE=InnoDB DEFAULT CHARSET=utf8;
    

    2. 插入数据

    INSERT INTO runoob_tbl (runoob_title, runoob_author, submission_date) VALUES("学习 PHP", "菜鸟教程", NOW());
    
    INSERT INTO runoob_tbl (runoob_title, runoob_author, submission_date) VALUES ("学习 MySQL", "菜鸟教程", NOW());
    
    INSERT INTO runoob_tbl (runoob_title, runoob_author, submission_date) VALUES ("JAVA 教程", "RUNOOB.COM", '2016-05-06');
    

    3.sql语句清空表数据

    数据表的清空有三种方式:

    1.delete------ 是逐行删除速度极慢,不适合大量数据删除。

    Delete from tablename where 1=1
    

    2.truncate---- 删除所有数据,保留表结构,不能撤消还原。

    TRUNCATE TABLE tablename
    

    3.drop-------- 删除表,数据和表结构一起删除,快速。

    SET FOREIGN_KEY_CHECKS=0;
    
    -- ----------------------------
    -- Table structure for docker2
    -- ----------------------------
    DROP TABLE IF EXISTS `docker2`;
    CREATE TABLE `docker2` (
      `name` varchar(255) NOT NULL,
      `path` varchar(500) DEFAULT NULL,
      `docker1_name` varchar(255) NOT NULL,
      `tag1` varchar(255) DEFAULT NULL,
      `tag2` varchar(255) DEFAULT NULL,
      `tag3` varchar(255) DEFAULT NULL,
      `tag4` varchar(255) DEFAULT NULL,
      `tag5` varchar(255) DEFAULT NULL,
      `tag6` varchar(255) DEFAULT NULL,
      `tag7` varchar(255) DEFAULT NULL,
      `tag8` varchar(255) DEFAULT NULL,
      `tag9` varchar(255) DEFAULT NULL,
      PRIMARY KEY (`docker1_name`,`name`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
    

    4.时间查询

    select * from DWD_D_FORECAST where to_char(TM1,'YYYY-MM-DD HH24:MI:SS')  = '2021-05-24 23:30:00'
    

    5. 查询表的结构

    fields = cursor.description
    print(fields)
    

    6. 表及其数据复制到另一个表

    https://bbs.csdn.net/topics/290046277
    https://zhidao.baidu.com/question/160923684.html

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