java mysql增删改查

Java与MySQL数据库交互，常用的是JDBC（Java Database Connectivity）技术。下面讲解Java中MySQL的增删改查操作，具体实现如下：

1. 建立连接

首先需要导入mysql-connector-java.jar包，然后使用如下代码建立连接：

String url = "jdbc:mysql://localhost:3306/数据库名?useUnicode=true&characterEncoding=utf-8&useSSL=false";
String user = "用户名";
String password = "密码";
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(url, user, password);

2. 增加数据

String sql = "insert into 表名(字段1, 字段2, …) values (?, ?, …)";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "value1");
pstmt.setString(2, "value2");
…
pstmt.executeUpdate();

3. 删除数据

String sql = "delete from 表名 where 条件";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.executeUpdate();

4. 修改数据

String sql = "update 表名 set 字段1 = ?, 字段2 = ?, … where 条件";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "value1");
pstmt.setString(2, "value2");
…
pstmt.executeUpdate();

5. 查询数据

String sql = "select 字段1, 字段2, … from 表名 where 条件";
PreparedStatement pstmt = conn.prepareStatement(sql);
ResultSet rs = pstmt.executeQuery();
while(rs.next()){
    String value1 = rs.getString("字段1");
    String value2 = rs.getString("字段2");
    …
}