java—DButils簡化JBDC操做

DButils實現增刪改

/**
 * 測試DButils的增刪改
 */
public class DBUtilsTest {

    /**
     * DButils 添加
     */
    @Test
    public void testadd(){
        try{
            QueryRunner qr = new QueryRunner();
            String sql = "insert into t1 value(?,?)";
            Object[] params = {9,"hhh"};
            Connection conn = C3P0utils.getConnection();
            int rows = qr.update(conn,sql,params);
            if (rows > 0) {
                System.out.println("添加成功!");
            } else {
                System.out.println("添加失敗!");
            }
        }catch (SQLException e){
            throw new RuntimeException(e);
        }
    }

    /**
     * DButils 更改
     */
    @Test
    public void testupdate(){
        try{
            QueryRunner qr = new QueryRunner();
            String sql = "update t1 set name=? where id = ?";
            Object[] params = {"sxf",9};
            Connection conn = C3P0utils.getConnection();
            int rows = qr.update(conn,sql,params);
            if (rows > 0) {
                System.out.println("修改爲功!");
            } else {
                System.out.println("修改失敗!");
            }
        }catch (SQLException e){
            throw new RuntimeException(e);
        }
    }

    /**
     * DButils 刪除
     */
    @Test
    public void testdel(){
        try{
            QueryRunner qr = new QueryRunner();
            String sql = "delete from t1 where id = ?";
            Object[] params = {7};
            Connection conn = C3P0utils.getConnection();
            int rows = qr.update(conn,sql,params);
            if (rows > 0) {
                System.out.println("刪除成功!");
            } else {
                System.out.println("刪除失敗!");
            }
        }catch (SQLException e){
            throw new RuntimeException(e);
        }
    }
}

 

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DButils 查詢   

BeanListHandler  查詢全部裝置list

BeanHandler　　指定第一天查詢信息

ScalarHandler　　用於單數據操做

public class DBUtilsTest2 {
    /**
     * 查詢全部
     */
    @Test
    public void testQueryAll() {
        try{
            QueryRunner qr = new QueryRunner();
            String sql = "select * from t1";
            Connection conn = C3P0utils.getConnection();
            List<user> users = qr.query(conn,sql,new BeanListHandler<user>(user.class));
            for(user u:users){
                System.out.println(u.getId() + " : " + u.getName());
            }
        }catch (SQLException e){
            throw new RuntimeException(e);
        }
    }

    /*
     * 根據id查詢用戶方法
     */
    @Test
    public void testQueryUserById() {
        try {
            // 1.獲取核心類queryRunner
            QueryRunner qr = new QueryRunner(C3P0utils.getDataSource());
            // 2.編寫sql語句
            String sql = "select * from t1 where id=?";
            //3.爲佔位符設置值
            Object[] params = {5};
            // 4.執行查詢操做
            user user = qr.query(sql, new BeanHandler<user>(user.class), params);
            System.out.println(user.getId() + " : " + user.getName());
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    /*
     * 根據全部用戶的總個數
     */
    @Test
    public void testQueryCount() {
        try {
            // 1.獲取核心類queryRunner
            QueryRunner qr = new QueryRunner(C3P0utils.getDataSource());
            // 2.編寫sql語句
            String sql = "select count(*) from t1";
            // 4.執行查詢操做
            Long count = (Long) qr.query(sql, new ScalarHandler());
            System.out.println(count);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }


}