DBUtil与修改
package org.chenao.utli;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class DBUtil {static{try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public static Connection getConn(){Connection conn = null;try {conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName= MyDB","sa","1");} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return conn;}public static void close(Connection conn, PreparedStatement ps, ResultSet rs) {try {if (conn!=null) {conn .close();}if (ps!=null) {ps .close();}if (rs!=null) {rs .close();}}catch (SQLException e) {e.printStackTrace();}}public static int update(String sql,Object[] objs){Connection conn = getConn();int count=0;PreparedStatement ps=null;try {ps = conn.prepareStatement(sql);for (int i = 0; i < objs.length; i++) {ps.setObject(i+1, objs[i]);}count=ps.executeUpdate();} catch (SQLException e) {e.printStackTrace();}finally{close(conn, ps, null);}return count;}
}
增加
package org.chenao.test;import org.chenao.utli.DBUtil;public class InsertTest {public static void main(String[] args) {String sql= "insert into user (name,age，pwd)values(?,?,?)";Object[] objs={"張三",25,"123456"};int count= DBUtil.update(sql, objs);if (count>0) {System.out.println("插入成功");} else {System.out.println("插入失敗");}}}
删除
package org.chenao.test;import org.chenao.utli.DBUtil;public class DeleceTest {public static void main(String[] args) {String sql= "update user set pwd=? where id=?";Object[] objs={"123456",2};int count= DBUtil.update(sql, objs);if (count>0) {System.out.println("修改成功");} else {System.out.println("修改失敗");}}}
查询
package org.chenao.test;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;import org.chenao.utli.DBUtil;public class SelectTest {public static void main(String[] args) throws SQLException {Connection conn =DBUtil.getConn(); String sql= "select from * user";Object[] objs={"123456",2};PreparedStatement ps = conn.prepareStatement(sql);ResultSet rs= ps.executeQuery();while (rs.next()) {System.out.println(rs.getInt(1));System.out.println(rs.getString(2));System.out.println(rs.getString(3));}}}