• mysql系列3 SQL语法基础


    1.创建数据库(语法)

      

      

    2.创建(数据库)表(语法)

      

     

        复制新的空表举个例子:

          

    mysql> use course;
    Reading table information for completion of table and column names
    You can turn off this feature to get a quicker startup with -A

    Database changed
    mysql> show tables;
    +------------------+
    | Tables_in_course |
    +------------------+
    | students |
    +------------------+
    1 row in set (0.00 sec)

    mysql> desc students;
    +--------+-------------+------+-----+---------+-------+
    | Field | Type | Null | Key | Default | Extra |
    +--------+-------------+------+-----+---------+-------+
    | id | int(11) | YES | | NULL | |
    | name | varchar(16) | YES | | NULL | |
    | gender | int(11) | YES | | NULL | |
    +--------+-------------+------+-----+---------+-------+
    3 rows in set (0.01 sec)

    mysql> insert into students values('1','lili','01'),('2','hanmeimei','02');
    Query OK, 2 rows affected (0.04 sec)
    Records: 2 Duplicates: 0 Warnings: 0

    mysql> select * from students;
    +------+-----------+--------+
    | id | name | gender |
    +------+-----------+--------+
    | 1 | lili | 1 |
    | 2 | hanmeimei | 2 |
    +------+-----------+--------+
    2 rows in set (0.00 sec)

    mysql> create table students_copy like students;
    Query OK, 0 rows affected (0.13 sec)

    mysql> show tables;
    +------------------+
    | Tables_in_course |
    +------------------+
    | students |
    | students_copy |
    +------------------+
    2 rows in set (0.01 sec)

    mysql> desc students_copy;
    +--------+-------------+------+-----+---------+-------+
    | Field | Type | Null | Key | Default | Extra |
    +--------+-------------+------+-----+---------+-------+
    | id | int(11) | YES | | NULL | |
    | name | varchar(16) | YES | | NULL | |
    | gender | int(11) | YES | | NULL | |
    +--------+-------------+------+-----+---------+-------+
    3 rows in set (0.00 sec)

    mysql> desc students;
    +--------+-------------+------+-----+---------+-------+
    | Field | Type | Null | Key | Default | Extra |
    +--------+-------------+------+-----+---------+-------+
    | id | int(11) | YES | | NULL | |
    | name | varchar(16) | YES | | NULL | |
    | gender | int(11) | YES | | NULL | |
    +--------+-------------+------+-----+---------+-------+
    3 rows in set (0.00 sec)

     

     

     

       创建索引例子:    

    mysql> show tables
    -> ;
    +------------------+
    | Tables_in_course |
    +------------------+
    | students |
    | students_copy |
    | students_copy01 |
    | students_copy02 |
    | students_copy03 |
    +------------------+
    5 rows in set (0.00 sec)

    mysql> select * from students;
    +----+-----------+--------+
    | id | name | gender |
    +----+-----------+--------+
    | 1 | lili | 1 |
    | 2 | hanmeimei | 2 |
    +----+-----------+--------+
    2 rows in set (0.00 sec)

    mysql> create index index01 on students(name);
    Query OK, 0 rows affected (0.55 sec)
    Records: 0 Duplicates: 0 Warnings: 0

     

     

     

     

     

        

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  • 原文地址:https://www.cnblogs.com/renyongbin/p/11925822.html
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