让我们首先创建一个表 - mysql> create table DemoTable1908    (    Code text    ); Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1908 values('MySQL(1)Database'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1908 values('MongoDB 2 Database'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1908 values('MySQL(3)Database'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1908 values('SQL Server(10)Database'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1908 values('MySQL 8 Database'); Query OK, 1 row affected (0.00 sec)显示所有记录从 ... 阅读更多

让我们首先创建一个表 - mysql> create table DemoTable1907    (    UserId int NOT NULL AUTO_INCREMENT,    UserName varchar(20),    UserAge int,    UserCountryName varchar(20),    PRIMARY KEY(UserId)    )ENGINE=MyISAM, AUTO_INCREMENT=100; Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1907(UserName, UserAge, UserCountryName) values('Chris', 26, 'US'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1907(UserName, UserAge, UserCountryName) values('David', 38, 'UK'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1907(UserName, UserAge, UserCountryName) values('John', 28, 'AUS'); Query OK, 1 row affected (0.00 sec)显示所有记录从 ... 阅读更多

要更改日期格式，请使用 DATE_FORMAT() 函数。让我们首先创建一个表 - mysql> create table DemoTable1906    (    DueTime datetime    ); Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1906 values(now()); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1906 values(curdate()); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1906 values('2017-10-11'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1906 values('2015-01-12'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1906 values('2018-04-25'); Query OK, 1 row affected (0.00 ... 阅读更多

要加快该过程，可以使用 INDEX。让我们首先创建一个表 - mysql> create table DemoTable1905    (    FirstName varchar(20),    LastName varchar(20) ,    INDEX F_L_Name(FirstName, LastName)    ); Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1905 values('John', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1905 values('John', 'Doe'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1905 values('Adam', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1905 values('John', 'Doe'); Query OK, 1 row affected (0.00 sec) ... 阅读更多

要转义反斜杠，请在插入记录时使用 PreparedStatement。让我们首先创建一个表 - mysql> create table DemoTable1904    (    ClientId int,    ClientName varchar(20),    ClientAge int    ); Query OK, 0 rows affected (0.00 sec)Java 代码如下 - import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; public class EscapeBackslashesDemo {    public static void main(String[] args) {       Connection con = null;       PreparedStatement ps = null;       try {          con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/web?" + "useSSL=false", "root", "123456");          String query = "insert into DemoTable1904(ClientId, ... 阅读更多

让我们首先创建一个表 - mysql> create table DemoTable1903    (    FirstName varchar(20),    LastName varchar(20) ,    Age int    ); Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1903 values('John', 'Smith', 23); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('None', 'Miller', 28); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('None', 'Taylor', 26); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('Chris', 'Brown', 26); Query OK, 1 row affected (0.00 sec)显示所有记录从表 ... 阅读更多

为此，请使用 REGEXP。让我们首先创建一个表 - mysql> create table DemoTable1902    (    Subjects text    ); Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1902 values('MongoDB, Java, Python'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1902 values('SQL Server, MySQL, PL/SQL'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1902 values('Hibernate, Spring, JPA'); Query OK, 1 row affected (0.00 sec)使用 select 语句显示表中的所有记录 - mysql> select * from DemoTable1902;这将产生以下输出 -+-------------------------+ | Subjects ... 阅读更多

为此，您可以使用 INSERT INTO SELECT 语句。让我们首先创建一个表 - mysql> create table DemoTable1900    (    ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    ClientName varchar(20),    ClientAge int default 29    ) auto_increment=1000; Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1900(ClientName, ClientAge) values('Chris', 45); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1900(ClientName, ClientAge) values('David', 29); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1900(ClientName, ClientAge) values('Mike', 37); Query OK, 1 row affected (0.00 sec) mysql> insert into ... 阅读更多

要替换特定字符，请使用 REPLACE()，要更新，请使用 UPDATE 命令。让我们首先创建一个表 - mysql> create table DemoTable1899    (    Code varchar(20)    ); Query OK, 0 rows affected (0.00 sec)使用 insert 命令在表中插入一些记录 - mysql> insert into DemoTable1899 values('John_123'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1899 values('32189_Sam_987'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1899 values('Miller_David_456_909'); Query OK, 1 row affected (0.00 sec)使用 select 语句显示表中的所有记录 - mysql> select * from DemoTable1899;这将产生以下输出 ... 阅读更多

让我们首先创建一个表 -mysql> create table DemoTable1898    (    Number int    ); Query OK, 0 rows affected (0.00 sec)使用insert命令在表中插入一些记录 -mysql> insert into DemoTable1898 values(10); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(70); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(30); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(50); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(40); Query OK, 1 row affected (0.00 sec)使用select语句显示表中的所有记录 ... 阅读更多