找到 4379 篇文章 适用于 MySQL
93 次浏览
让我们首先创建一个表 - mysql> create table DemoTable649 (Value text); Query OK, 0 rows affected (0.68 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable649 values('1903'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable649 values('9321010'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable649 values('983032023393'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable649 values('1234567892'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable649 values('989898989'); Query OK, 1 row affected (0.20 sec)使用 select 语句显示表中的所有记录 - mysql> select *from DemoTable649;这将... 阅读更多
446 次浏览
让我们首先创建一个表。其中一列设置为 TIMESTAMP - mysql> create table DemoTable648( UserId int NOT NULL AUTO_INCREMENT, UserLoginTime TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP, PRIMARYKEY(UserId) ); Query OK, 0 rows affected (0.66 sec)使用 insert 命令在表中插入一些记录。在这里,我们使用 NOW() 方法将当前日期和时间设置为时间戳列 - mysql> insert into DemoTable648(UserLoginTime) values(NOW()); Query OK, 1 row affected (0.22 sec)使用 select 语句显示表中的所有记录 - mysql> select *from DemoTable648;这将产生以下输出 - +--------+---------------------+ | UserId | UserLoginTime ... 阅读更多
119 次浏览
使用 RAND() 获取随机值,而 LIMIT 3 用于值的个数,此处为 3 - select yourColumnName from yourTableName order by rand() limit 3;让我们首先创建一个表 - mysql> create table DemoTable646 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(100) ); Query OK, 0 rows affected (0.76 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable646(FirstName) values('John'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable646(FirstName) values('Bob'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable646(FirstName) values('Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable646(FirstName) ... 阅读更多
381 次浏览
为此,使用 UNION。让我们首先创建一个表 - mysql> create table DemoTable645 (Id int, FirstName varchar(100)); Query OK, 0 rows affected (0.67 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable645 values(100, 'Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable645 values(101, 'Robert'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable645 values(101, 'Bob'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable645 values(102, 'Carol'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable645 values(100, 'John'); Query OK, 1 row affected (0.12 sec) mysql> insert ... 阅读更多
132 次浏览
为此,使用 CONCAT()。让我们首先创建一个表 - mysql> create table DemoTable644 (Title text); Query OK, 0 rows affected (0.81 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable644 values('Introduction'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable644 values('Welcome in course'); Query OK, 1 row affected (0.10 sec)使用 select 语句显示表中的所有记录 - mysql> select *from DemoTable644;这将产生以下输出 - +-------------------+ | Title | +-------------------+ | Introduction | | Welcome in course | +-------------------+ 2 rows ... 阅读更多
168 次浏览
让我们首先创建一个表 - mysql> create table DemoTable643 (ClientId int); Query OK, 0 rows affected (0.86 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable643 values(1000); Query OK, 1 row affected (0.19 sec)使用 select 语句显示表中的所有记录 - mysql> select *from DemoTable643;这将产生以下输出 - +----------+ | ClientId | +----------+ | 1000 | +----------+ 1 row in set (0.00 sec)以下是带有 IF THEN END IF 的 MySQL 存储过程的查询 - mysql> DELIMITER // mysql> CREATE PROCEDURE IF_DEMO(argument int) BEGIN DECLARE firstArgument int; DECLARE ... 阅读更多
128 次浏览
让我们首先创建一个表 - mysql> create table DemoTable642( EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY, EmployeeName archar(100), EmployeeCompanyNamevarchar(100) ); Query OK, 0 rows affected (0.81 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable642(EmployeeName, EmployeeCompanyName) values('John', 'Google'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable642(EmployeeName, EmployeeCompanyName) values('Carol', 'Microsoft'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable642(EmployeeName, EmployeeCompanyName) values('John', 'Amazon'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable642(EmployeeName, EmployeeCompanyName) values('Carol', 'Google'); Query OK, 1 row affected (0.37 sec) mysql> insert into DemoTable642(EmployeeName, EmployeeCompanyName) values('John', 'Flipkart'); ... 阅读更多
203 次浏览
让我们首先创建一个表 - mysql> create table DemoTable1 (Id int, Name varchar(100)); Query OK, 0 rows affected (0.89 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1 values(100, 'John'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1 values(110, 'Chris'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1 values(120, 'Robert'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1 values(130, 'David'); Query OK, 1 row affected (0.14 sec)使用 select 语句显示表中的所有记录 - mysql> select *from DemoTable1;这将产生以下输出 - +------+--------+ | ... 阅读更多
145 次浏览
为此,您需要将 AUTO_INCREMENT 设置为 1000 - alter table yourTableName AUTO_INCREMENT = 1000;让我们首先创建一个表 - mysql> create table DemoTable639 ( StudentId int PRIMARY KEY, StudentStartId int AUTO_INCREMENT, StudentName VARCHAR(50), INDEX(StudentStartId) ); Query OK, 0 rows affected (0.86 sec)以下是将自动递增设置为 1000 的查询 - mysql> alter table DemoTable639 AUTO_INCREMENT = 1000; Query OK, 0 rows affected (0.28 sec) Records: 0 Duplicates: 0 Warnings: 0使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable639(StudentId, StudentName) values(1, 'John'); Query OK, 1 row affected (0.17 sec) mysql> ... 阅读更多
329 次浏览
首先,让我们创建一个表 −mysql> create table DemoTable638 (Name varchar(100), Marks int); Query OK, 0 rows affected (0.68 sec)使用 insert 命令在表中插入一些记录 −mysql> insert into DemoTable638 values('John', 67); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable638 values('John', 90); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable638 values('David', 99); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable638 values('John', 60); 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 DemoTable638;这将产生以下输出 −+-------+-------+ | ... 阅读更多