MySQL links, viewing databases, working with databases, viewing tables

MySQL links, viewing databases, working with databases, viewing tables

Mysql> Show databases;+--------------------+| Database |+--------------------+| Information_schema | | MySQL | | Performance_schema | | QQ | | Test |+--------------------+5 rows in Set (0.06 sec) mysql> use qq;database changedmysql> desc QQ; ERROR 1146 (42S02): Table ' qq.qq ' doesn ' t existmysql> desc Table; Error 1064 (42000): You have a error in your SQL syntax;  Check the manual-corresponds to your MySQL server version for the right syntax-use near ' table ' at line 1mysql> Set name GBK; ERROR 1193 (HY000): Unknown system variable ' name ' mysql> set names GBK; Query OK, 0 rows Affected (0.00 sec) mysql> Show tables;+--------------+| TABLES_IN_QQ |+--------------+| Stu |+--------------+1 row in Set (0.01 sec) mysql> desc stu;+-------+------------+------+-----+---------+----- --+| Field | Type | Null | Key | Default | Extra |+-------+------------+------+-----+---------+-------+| ID | Int (11) | YES | |       NULL | || name | varchar (4) |     YES | |       NULL | |+-------+------------+------+-----+---------+-------+2 rows in Set (0.02 sec) mysql> SELECT * FROM stu;+------+----- -+| ID |    Name |+------+------+| 1 | Lisi | | NULL | John Doe |+------+------+2 rows in Set (0.01 sec) mysql> insert into Stu values, (2, ' Zhangsan '); ERROR 1406 (22001): Data too long for column ' name ' @ row 1mysql> insert into STU values---(2, ' Zhangsan ')-& Gt (3, ' Zhan '); Error 1064 (42000): You have a error in your SQL syntax; Check the manual-corresponds to your MySQL server version for the right syntax-use-near ' (3, ' Zhan ') ' on line 3mysq l> INSERT into STU values---(2, ' Zhan '); Query OK, 1 row Affected (0.00 sec) mysql> Show tables;+--------------+| TABLES_IN_QQ |+--------------+| Stu |+--------------+1 row in Set (0.00 sec) mysql> Select (name) from stu;+------+| Name |+------+| Lisi | | John Doe | | Zhan |+------+3 rows in Set (0.00 sec) mysql> Delete form where id=3; Error 1064 (42000): You have a error in your SQL syntax; Check the manual-corresponds to your MySQL server version for the right syntax-use near ' where id=3 ' at line 1mysq L> Delete from Stu where id=3; Query OK, 0 rows affected (0.02 sec) mysql> Select (name) from stu;+------+| Name |+------+| Lisi | | John Doe | | Zhan |+------+3 rows in Set (0.00 sec) mysql> SELECT * FROM stu;+------+------+| ID |    Name |+------+------+| 1 | Lisi | | NULL |    John Doe | | 2 | Zhan |+------+------+3 rows in Set (0.00 sec) mysql> Delete from Stu where id, id=null; Error 1064 (42000): You have a error in your SQL syntax; Check the manual-corresponds to your MySQL server version for the right syntax-use-near ' id=null ' on line 2MYSQL&G T Delete from Stu where id=null; Query OK, 0 rows Affected (0.00 sec) mysql> Delete from Stu where id=null; Query OK, 0 rows Affected (0.00 sec) mysql> Delete from Stu where id= '; Query OK, 0 rows Affected (0.00 sec) mysql> Delete from Stu where id=2; Query OK, 1 row Affected (0.00 sec) mysql> SELECT * FROM stu;+------+------+| ID |    Name |+------+------+| 1 | Lisi | | NULL | John Doe |+------+------+2 rows in Set (0.00 sec) mysql> INSERT into CLASSS,/C-\cmysql> mysql> Inse RT into Class (\cmysql> Create TABLE class (ID int primary KEY auto_increment, sname varchar    (+) NOT NULL default ", Gender char (1) NOT NULL default", "Company varchar", "NOT null default", -Salary Decimal (6,2) NOT NULL default 0.00--) engine MyISAM charset UTF8; Query OK, 0 rows affected (0.08 sec) mysql> desc class;+---------+--------------+------+-----+---------+------------ ----+| Field | Type | Null | Key | Default | Extra |+---------+--------------+------+-----+---------+----------------+| ID | Int (11) | NO | PRI | NULL | auto_increment | | sname | varchar (10) |     NO |         |      |          || Gender | char (1) |     NO |         |                | || Company | varchar (20) |     NO |         |                | || Salary | Decimal (6,2) |     NO | |                0.00 |    |+---------+--------------+------+-----+---------+----------------+5 rows in Set (0.00 sec) mysql> insert INTO class Values---1, ' Zhang San ', ' Male ', ' Baidu ', 7000; Query OK, 1 row affected (0.03 sec) mysql> Show Table from class; Error 1064 (42000): You have a error in your SQL syntax; Check the manual-corresponds to your MySQL server version for the right syntax-use near ' from class ' at line 1mysq L> select * Form class; Error 1064 (42000): You have a error in your SQL syntax; Check the manual-corresponds to your MySQL server version for the right syntax-use near ' form class ' at line 1mysq L> SELECT * from class;+----+-------+--------+---------+---------+| ID | sname | Gender | Company |  Salary |+----+-------+--------+---------+---------+| 1 | Zhang San |Male | Baidu | 7000.00 |+----+-------+--------+---------+---------+1 row in Set (0.01 sec) mysql> insert INTO, name,gender,com pany), values---' Lisi ', ' Male ', ' IBM '; Error 1064 (42000): You have a error in your SQL syntax; Check the manual-corresponds to your MySQL server version for the right syntax-use-near ' (Name,gender,company) Valu Es (' Lisi ', ' Male ', ' IBM ') ' at line 2mysql> insert into Class (Name,gender,company), values---' Lisi ' , ' Male ', ' IBM '); ERROR 1054 (42S22): Unknown column ' name ' in ' field List ' mysql> insert into Class (Sname,gender,company)-& Gt Values--(' Lizi ', ' Male ', ' IBM '); Query OK, 1 row Affected (0.00 sec) mysql> SELECT * from class;+----+-------+--------+---------+---------+| ID | sname | Gender | Company |  Salary |+----+-------+--------+---------+---------+| 1 | Zhang San | Male | Baidu |  7000.00 | | 2 | Lizi | Male |    IBM | 0.00 |+----+-------+--------+---------+---------+2 rows in Set (0.00 sec) mysql> SELECT * from class where company; Empty set, 2 Warnings (0.00 sec) mysql> SELECT * from class;+----+-------+--------+---------+---------+| ID | sname | Gender | Company |  Salary |+----+-------+--------+---------+---------+| 1 | Zhang San | Male | Baidu |  7000.00 | | 2 | Lizi | Male |    IBM | 0.00 |+----+-------+--------+---------+---------+2 rows in Set (0.00 sec) mysql> Select Company from class;+---------+ | Company |+---------+| Baidu | | IBM |+---------+2 rows in Set (0.00 sec) mysql> SELECT * from class where id=2;+----+-------+--------+---------+---- ----+| ID | sname | Gender | Company |  Salary |+----+-------+--------+---------+--------+| 2 | Lizi | Male |   IBM | 0.00 |+----+-------+--------+---------+--------+1 row in Set (0.00 sec) mysql> #改, which table to change, which columns, which rows, to what value. Mysql> Update class, set salary=7800, where id=2; Query OK, 1 row affected (0.01 sec) Rows matched:1 changed:1 Warnings:0mysql> SELECT * from class;+----+-------+--------+---------+---------+| ID | sname | Gender | Company |  Salary |+----+-------+--------+---------+---------+| 1 | Zhang San | Male | Baidu |  7000.00 | | 2 | Lizi | Male | IBM | 7800.00 |+----+-------+--------+---------+---------+2 rows in Set (0.02 sec)

MySQL links, viewing databases, working with databases, viewing tables