JDBC练习_update_DDL语句

删除一条记录:

public static void main(String[] args) {

        Connection conn = null;

        Statement stmt = null;

        try {

            //1. 注册驱动

            Class.forName("com.mysql.jdbc.Driver");

            //2.获取连接对象

            conn = DriverManager.getConnection("jdbc:mysql:///db3", "root", "root");

           //conn = JDBCUtils.getConnection("jdbc:mysql:///db3", "root", "root");

            //3.定义sql

            String sql  = "delete from account where id = 3";

            //4.获取执行sql对象

            stmt = conn.createStatement();

            //5.执行sql

            int count = stmt.executeUpdate(sql);

            //6.处理结果

            System.out.println(count);

            if(count > 0){

                System.out.println("删除成功!");

            }else{

                System.out.println("删除失败");

            }

 

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        } catch (SQLException e) {

            e.printStackTrace();

        } finally {

            //7.释放资源

 

            if(stmt != null){

                try {

                    stmt.close();

                } catch (SQLException e) {

                    e.printStackTrace();

                }

            }

 

            if(conn != null){

                try {

                    conn.close();

                } catch (SQLException e) {

                    e.printStackTrace();

                }

            }

        }

}

创建一张表:

public static void main(String[] args) {

        Connection conn = null;

        Statement stmt = null;

        try {

            //1. 注册驱动

            Class.forName("com.mysql.jdbc.Driver");

            //2.获取连接对象

            conn = DriverManager.getConnection("jdbc:mysql:///db3", "root", "root");

            //3.定义sql

            String sql  = "create table student (id int , name varchar(20))";

            //4.获取执行sql对象

            stmt = conn.createStatement();

            //5.执行sql

            int count = stmt.executeUpdate(sql);

            //6.处理结果

            System.out.println(count);

 

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        } catch (SQLException e) {

            e.printStackTrace();

        } finally {

            //7.释放资源

 

            if(stmt != null){

                try {

                    stmt.close();

                } catch (SQLException e) {

                    e.printStackTrace();

                }

            }

 

            if(conn != null){

                try {

                    conn.close();

                } catch (SQLException e) {

                    e.printStackTrace();

                }

            }

        }

    }

 

 

总结 :

注意这里需要使用statementexecuteUpdate(sql),方法,并关闭连接connectionstatement

JDBC练习_update_DDL语句

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