Mysql----浅入浅出之JDBC连接

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JDBC连接数据库的步骤:

一、在开发环境中加载驱动:

我用的是Mysql,所以下载了mysql-connector-java-5.1.24-bin.jar

在eclipse中建立新项目,在项目的buildpath中引入这个包。


二、在程序中加载驱动:

通过Class.forName("com.mysql.jdbc.Driver"); 来加载数据驱动程序。


三、建立数据库连接对象:

DriverManager.getConnection("jdbc:mysql://127.0.0.1/databasename", "username", "password");

这个方法得到一个数据连接对象。


四、Statement对象:

这个对象是用来执行sql语句的,假设前面我们得到的连接对象叫con。那么下面的方法可以读到一个Statement对象

con.createStatement();


五、接下来就可以执行sql语句了:

statement.execute(String yourSql);

statement有很多execute方式,根据不同需要来选择,会得到不同的反馈。


六、关闭连接:

con.close();


import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.sql.Connection;public class testJDBC {static Connection conn = null;static Statement stm = null;public static void main(String[] args){conn = connect();show();insert("LiuWeiZheng", 21, "woman");delete("wanglu");show();}public static void delete(String name){String sql = "delete from mytable where name = \"" + name + "\";";try {stm = conn.createStatement();int num = stm.executeUpdate(sql);if(num != 0)System.out.println("成功删除" + name);} catch (SQLException e) {System.out.println("删除失败");}}public static void show(){String sql = "Select * from mytable order by age desc";try {stm = conn.createStatement();ResultSet rs = stm.executeQuery(sql);System.out.println("查询结果:");while(rs.next()){String name = rs.getString("name");int age = rs.getInt("age");String sex = rs.getString("sex");System.out.println("name: " + name + "---age: " + age + "---sex: " + sex);}} catch (SQLException e) {e.printStackTrace();}}public static void insert(String name ,int age, String sex){String sql = "insert into mytable values(\"" + name + "\"," + age + ",\"" + sex + "\");";try {stm = conn.createStatement();stm.execute(sql);} catch (SQLException e) {System.out.println("插入失败");}}public static Connection connect(){Connection con = null;try {Class.forName("com.mysql.jdbc.Driver");con = DriverManager.getConnection("jdbc:mysql://127.0.0.1/testjdbc", "root", "008421");} catch (ClassNotFoundException e) {System.out.println("加载驱动出错");} catch (SQLException e) {System.out.println("连接数据库出错");}return con;}}

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