Java对数据库增删改查
时间: 2023-10-02 22:11:19 浏览: 47
在 Java 中进行数据库的增删改查操作可以通过 JDBC(Java Database Connectivity)来实现。以下是一个简单的示例代码:
首先,确保您已经安装了适当的数据库驱动程序,并在项目中引入相关的库。
连接数据库:
```java
import java.sql.*;
public class DatabaseConnector {
private static final String DB_URL = "jdbc:mysql://localhost:3306/mydatabase";
private static final String USER = "username";
private static final String PASS = "password";
public static Connection getConnection() throws SQLException {
return DriverManager.getConnection(DB_URL, USER, PASS);
}
}
```
插入数据:
```java
import java.sql.*;
public class InsertData {
public static void main(String[] args) {
try (Connection conn = DatabaseConnector.getConnection();
Statement stmt = conn.createStatement()) {
String sql = "INSERT INTO students (name, age) VALUES ('John', 25)";
stmt.executeUpdate(sql);
System.out.println("Data inserted successfully.");
} catch (SQLException e) {
e.printStackTrace();
}
}
}
```
查询数据:
```java
import java.sql.*;
public class RetrieveData {
public static void main(String[] args) {
try (Connection conn = DatabaseConnector.getConnection();
Statement stmt = conn.createStatement()) {
String sql = "SELECT * FROM students";
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println("Name: " + name + ", Age: " + age);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
```
更新数据:
```java
import java.sql.*;
public class UpdateData {
public static void main(String[] args) {
try (Connection conn = DatabaseConnector.getConnection();
Statement stmt = conn.createStatement()) {
String sql = "UPDATE students SET age = 30 WHERE name = 'John'";
int rowsAffected = stmt.executeUpdate(sql);
System.out.println("Rows affected: " + rowsAffected);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
```
删除数据:
```java
import java.sql.*;
pu