要实现多个 LIKE 子句，语法如下：select * from yourTableName where yourColumnName1 LIKE ('%yourValue1%' or yourColumnName2 LIKE '%yourValue2%') or (yourColumnName3 LIKE '%yourValue3');让我们先创建一个表：mysql> create table DemoTable1534 -> ( -> ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> ClientName varchar(20), -> ClientAge int, -> ClientCountryName varchar(20) -> ); Query OK, 0 rows affected (0.78 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable1534(ClientName, ClientAge, ClientCountryName) values('Chris Brown', 29, 'AUS'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable1534(ClientName, ClientAge, ClientCountryName) ... 阅读更多

让我们先创建一个表：mysql> create table DemoTable -> ( -> Value int -> ); Query OK, 0 rows affected (1.33 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable values(25); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(75); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.13 sec)使用 select 语句显示表中的所有记录：mysql> select * from DemoTable;这将产生以下输出：+-------+ | Value | +-------+ | 25 | | ... 阅读更多

为此，在 MySQL 中使用 INET_ATON()。INET_ATON() 方法允许用户将 IP 地址记录转换为数字，然后我们可以使用 ORDER BY 对其进行排序。让我们先创建一个表：mysql> create table DemoTable -> ( -> IpAddress varchar(50) -> ); Query OK, 0 rows affected (1.36 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable values('192.168.110.78'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('192.168.110.87'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values('192.168.110.75'); Query OK, 1 row affected (0.26 ... 阅读更多

为此，使用子查询以及 MIN() 和 MAX()。要显示最大值和最小值，请使用 UNION ALL。让我们先创建一个表：mysql> create table DemoTable -> ( -> EmployeeName varchar(20), -> EmployeeSalary int -> ); Query OK, 0 rows affected (0.70 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable values('Bob', 8800); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Chris', 9800); Query OK, 1 row affected (0.63 sec) mysql> insert into DemoTable values('David', 7600); Query OK, 1 row affected (0.11 sec) mysql> ... 阅读更多

要在 MySQL 中从多个表中计算行，语法如下：Select (select count(*) from yourTableName1) as anyAliasName1, (select count(*) from yourTableName2) as anyAliasName2 from dual;让我们先创建一个表：mysql> create table DemoTable1 -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY -> ); Query OK, 0 rows affected (0.56 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable1 values(), (), (), (), (), (); Query OK, 6 rows affected (0.24 sec) Records: 6 Duplicates: 0 Warnings: 0显示... 阅读更多

MySQL 等同于 sybase ASE 命令的是 EXPLAIN 关键字。让我们先创建一个表：mysql> create table DemoTable1531 -> ( -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(20) -> ); Query OK, 0 rows affected (2.92 sec) mysql> create index Name_index1 on DemoTable1531(StudentName); Query OK, 0 rows affected (0.99 sec) Records: 0 Duplicates: 0 Warnings: 0使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable1531(StudentName) values('Chris'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1531(StudentName) values('Robert'); Query OK, 1 row affected (0.10 sec) mysql> insert into ... 阅读更多

为此，使用 AVG()。要查找最大平均值，请使用 MAX() 并按 id 分组。让我们先创建一个表：mysql> create table DemoTable -> ( -> PlayerId int, -> PlayerScore int -> ); Query OK, 0 rows affected (0.55 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable values(1, 78); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(2, 82); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable values(1, 45); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(3, 97); ... 阅读更多

为此，使用 INSERT INTO SELECT 语句。让我们先创建一个表：mysql> create table DemoTable1 -> ( -> PersonId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> PersonName varchar(20), -> PersonAge int, -> PersonCountryName varchar(20) -> ); Query OK, 0 rows affected (0.55 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable1(PersonName, PersonAge, PersonCountryName) values('Chris Brown', 24, 'US'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1(PersonName, PersonAge, PersonCountryName) values('John Doe', 26, 'UK'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable1(PersonName, PersonAge, PersonCountryName) values('David ... 阅读更多

让我们先创建一个表：mysql> create table DemoTable -> ( -> ClientId int, -> Value int -> ); Query OK, 0 rows affected (0.79 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable values(10, 678); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(20, 678); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(30, 678); Query OK, 1 row affected (0.09 sec)使用 select 语句显示表中的所有记录：mysql> select *from DemoTable;这将产生以下输出：+----------+-------+ | ClientId | Value ... 阅读更多

让我们先创建一个表：mysql> create table DemoTable1528 -> ( -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(20), -> StudentSubject varchar(20) -> ); Query OK, 0 rows affected (0.53 sec)使用 insert 命令在表中插入一些记录：mysql> insert into DemoTable1528(StudentName, StudentSubject) values('Chris', 'MongoDB'); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable1528(StudentName, StudentSubject) values('Bob', 'MySQL'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1528(StudentName, StudentSubject) values('David', 'Java'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1528(StudentName, StudentSubject) values('Carol', 'C'); Query OK, 1 ... 阅读更多