为此，您可以创建一个存储过程。让我们先创建一个表。mysql> create table DemoTable - > ( - > Value int - > ); Query OK, 0 rows affected (0.55 sec)以下是创建存储过程的查询，该存储过程可从范围 10 到 20 自动将值插入表中 -mysql> DELIMITER // mysql> CREATE PROCEDURE AutoInsertValuesToTable() - > BEGIN - > - >DECLARE startingRange INT DEFAULT 10; - > - >WHILE startingRange - > - > - > INSERT DemoTable(Value) VALUES (startingRange ); - > - > - > SET startingRange = startingRange + 1; - > - > ... 阅读更多

让我们先创建一个表 -mysql> create table DemoTable - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > Number int - > ); Query OK, 0 rows affected (0.50 sec)使用 insert 命令在表中插入一些记录 -mysql> insert into DemoTable(Number) values(10); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Number) values(20); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Number) values(30); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Number) values(40); Query OK, 1 row affected (0.14 sec) 显示所有记录 ... 阅读更多

使用即不等于在 MySQL 中从表中排除特定行。让我们先创建一个表 -mysql> create table DemoTable - > ( - > Id int, - > FirstName varchar(100) - > ); Query OK, 0 rows affected (0.58 sec)使用 insert 命令在表中插入一些记录 -mysql> insert into DemoTable values(1, 'John'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(2, 'Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(3, 'Robert'); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable ... 阅读更多

为此，您可以使用 GROUP BY HAVING 子句。让我们先创建一个表 -mysql> create table DemoTable - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > Subject varchar(100) - > ); 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 DemoTable(Subject) values('MySQL'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(Subject) values('MongoDB'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable(Subject) values('MySQL'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(Subject) values('Java'); Query OK, 1 ... 阅读更多

为此，您可以使用 MySQL 的 concat() 函数。让我们先创建一个表 -mysql> create table DemoTable - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > Name varchar(20), - > Subject varchar(100) - > ); Query OK, 0 rows affected (17.73 sec)使用 insert 命令在表中插入一些记录 -mysql> insert into DemoTable(Name, Subject) values('John', 'MySQL'); Query OK, 1 row affected (1.19 sec) mysql> insert into DemoTable(Name, Subject) values('Chris', 'SQL Server'); Query OK, 1 row affected (0.88 sec) mysql> insert into DemoTable(Name, Subject) values('Robert', 'MongoDB'); Query OK, 1 row affected ... 阅读更多

让我们先创建一个表 -mysql> create table DemoTable - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > Name varchar(20) - > ); Query OK, 0 rows affected (0.69 sec)使用 insert 命令在表中插入一些记录 -mysql> insert into DemoTable(Name) values('Carol'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Name) values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Name) values('David'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(Name) values('Bob'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(Name) ... 阅读更多

如果给定一个包含文件路径的字符串，PHP basename() 函数将返回文件的基名称。要在 MySQL 中获得等效项，您可以使用 SUBSTRING_INDEX()。让我们先创建一个表 -mysql> create table DemoTable - > ( - > Location varchar(200) - > ); Query OK, 0 rows affected (1.02 sec)使用 insert 命令在表中插入一些记录 -mysql> insert into DemoTable values('C:\Web\Sum.java'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('E:\WebDevelopment\Image1.png'); Query OK, 1 row affected (0.42 sec)使用 select 语句显示表中的所有记录 ... 阅读更多

让我们先创建一个表 -mysql> create table DemoTable - > ( - > Name varchar(100) - > ); Query OK, 0 rows affected (0.85 sec)使用 insert 命令在表中插入一些记录 -mysql> insert into DemoTable values('John'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(NULL); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(NULL); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.17 sec)使用 select 语句显示表中的所有记录 -mysql> select *from DemoTable;Output+-------+ | Name ... 阅读更多

是的，我们可以使用 CASE 语句做到这一点。让我们先创建一个表 -mysql> create table DemoTable - > ( - > isMarried boolean - > ); 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 DemoTable values(true); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(false); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(false); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(true); Query OK, 1 row affected (0.19 sec)显示表中的所有记录 ... 阅读更多

要将时间转换为秒，请使用 TIME_TO_SEC() 方法。让我们先创建一个表 -mysql> create table DemoTable - > ( - > ArrivalTime time - > ); Query OK, 0 rows affected (0.63 sec)使用 insert 命令在表中插入一些记录 -mysql> insert into DemoTable values('04:10:00'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('05:20:50'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('06:40:10'); Query OK, 1 row affected (0.18 sec)使用 select 语句显示表中的所有记录 -mysql> select *from DemoTable;Output+-------------+ | ArrivalTime | +-------------+ | 04:10:00 ... 阅读更多