spring jdbc

引用jar包

Spring封装的jdbc引用的jar包

JDBCTemplate_介绍

JDBCTemplate_快速入门

导入jar包

JDBCTemplate_执行DML语句

添加注解

package cn.itcast.jdbctemplate;

import cn.itcast.utils.JDBCUtils;
import org.springframework.jdbc.core.JdbcTemplate;

/**

JdbcTemplate入门

*/
public class JdbcTemplateDemo1 {

public static void main(String[] args) {
    //1.导入jar包
    //2.创建JDBCTemplate对象
    JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());
    //3.调用方法
    String sql = "update account set balance = 5000 where id = ?";
    int count = template.update(sql, 3);
    System.out.println(count);
}

}

JDBCTemplate_执行DQL语句

package cn.itcast.jdbctemplate;

import cn.itcast.domain.Emp;
import cn.itcast.utils.JDBCUtils;
import org.junit.Test;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import java.sql.Date;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;

public class JdbcTemplateDemo2 {

//Junit单元测试，可以让方法独立执行


//1. 获取JDBCTemplate对象
private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());
/**
 * 1. 修改1号数据的 salary 为 10000
 */
@Test
public void test1(){

    //2. 定义sql
    String sql = "update emp set salary = 10000 where id = 1001";
    //3. 执行sql
    int count = template.update(sql);
    System.out.println(count);
}

/**
 * 2. 添加一条记录
 */
@Test
public void test2(){
    String sql = "insert into emp(id,ename,dept_id) values(?,?,?)";
    int count = template.update(sql, 1015, "郭靖", 10);
    System.out.println(count);

}

/**
 * 3.删除刚才添加的记录
 */
@Test
public void test3(){
    String sql = "delete from emp where id = ?";
    int count = template.update(sql, 1015);
    System.out.println(count);
}

/**
 * 4.查询id为1001的记录，将其封装为Map集合
 * 注意：这个方法查询的结果集长度只能是1
 */
@Test
public void test4(){
    String sql = "select * from emp where id = ? or id = ?";
    Map map = template.queryForMap(sql, 1001,1002);
    System.out.println(map);
    //{id=1001, ename=孙悟空, job_id=4, mgr=1004, joindate=2000-12-17, salary=10000.00, bonus=null, dept_id=20}

}

/**
 * 5. 查询所有记录，将其封装为List
 */
@Test
public void test5(){
    String sql = "select * from emp";
    List> list = template.queryForList(sql);

    for (Map stringObjectMap : list) {
        System.out.println(stringObjectMap);
    }
}

/**
 * 6. 查询所有记录，将其封装为Emp对象的List集合
 */

@Test
public void test6(){
    String sql = "select * from emp";
    List list = template.query(sql, new RowMapper() {

        @Override
        public Emp mapRow(ResultSet rs, int i) throws SQLException {
            Emp emp = new Emp();
            int id = rs.getInt("id");
            String ename = rs.getString("ename");
            int job_id = rs.getInt("job_id");
            int mgr = rs.getInt("mgr");
            Date joindate = rs.getDate("joindate");
            double salary = rs.getDouble("salary");
            double bonus = rs.getDouble("bonus");
            int dept_id = rs.getInt("dept_id");

            emp.setId(id);
            emp.setEname(ename);
            emp.setJob_id(job_id);
            emp.setMgr(mgr);
            emp.setJoindate(joindate);
            emp.setSalary(salary);
            emp.setBonus(bonus);
            emp.setDept_id(dept_id);

            return emp;
        }
    });


    for (Emp emp : list) {
        System.out.println(emp);
    }
}

/**
 * 6. 查询所有记录，将其封装为Emp对象的List集合
 */

@Test
public void test6_2(){
    String sql = "select * from emp";
    List list = template.query(sql, new BeanPropertyRowMapper(Emp.class));
    for (Emp emp : list) {
        System.out.println(emp);
    }
}

/**
 * 7. 查询总记录数
 */

@Test
public void test7(){
    String sql = "select count(id) from emp";
    Long total = template.queryForObject(sql, Long.class);
    System.out.println(total);
}

}

09 JDBCTemplate