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 block
e.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 block
e.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();
if (count>0) {
System.out.println("成功");
} else {
System.out.println("失败");
}
} 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 DeleteTest {
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));
}
}
}
