ARTICLE DETAIL

资讯详情

深耕网站建设、视觉设计与SEO优化的一线实战洞察。

JDBCTemplate基本使用

JDBCTemplate基本使用 开发步骤「1」导入spring-jdbc和spring-tx坐标dependency groupIdorg.springframework/groupId artifactIdspring-jdbc/artifactId version5.0.0.RELEASE/version /dependency dependency groupIdorg.springframework/groupId artifactIdspring-tx/artifactId version5.0.0.RELEASE/version /dependency「2」创建数据库和实体对象package com.Itheima.domain; public class Account { private String name; private Double balance; public String getName() { return name; } public void setName(String name) { this.name name; } public Double getBalance() { return balance; } public void setBalance(Double balance) { this.balance balance; } Override public String toString() { return super.toString(); } }public void testJdbcTemplate(){ // 创建数据源 ApplicationContext applicationContext new ClassPathXmlApplicationContext(applicationContext.xml); JdbcTemplate jdbcTemplate applicationContext.getBean(JdbcTemplate.class); int rows jdbcTemplate.queryForObject(select count(*) from person, Integer.class); int count jdbcTemplate.update(insert into account values (?,?), zhangsan,5000); }「3」创建JdbcTemplate对象!-- 加载外部的properties文件-- context:property-placeholder locationclasspath:jdbc.properties/ !-- 数据源对象-- bean iddataSource classcom.mchange.v2.c3p0.ComboPooledDataSource property namedriverClass value${jdbc.driver}/ property namejdbcUrl value${jdbc.url}/ property nameuser value${jdbc.username}/ property namepassword value${jdbc.password}/ /bean !-- jdbc模板对象-- bean idjdbcTemplate classorg.springframework.jdbc.core.JdbcTemplate property namedataSource refdataSource/ /beanjdbc.urljdbc:mysql://localhost:3306/test?serverTimezoneAsia/ShanghaiuseSSLfalse jdbc.usernameroot jdbc.passwordroot jdbc.drivercom.mysql.cj.jdbc.Driver「4」执行数据库操作增//1.新增数据 int insertRow jdbcTemplate.update(insert into account values (?,?),zhangsan,5000); System.out.println(新增影响行数insertRow);删Test public void testDelete(){ jdbcTemplate.update(delete from account where name?,jerry); }改Test public void testUpdate(){ jdbcTemplate.update(update account set balance? where name?,10000,jerry); }查此处的泛型就是你要封装的实体的泛型就是数据库对应的Java类Test public void testQueryAll(){ ListAccount query jdbcTemplate.query(select * from account, new BeanPropertyRowMapperAccount(Account.class)); System.out.println(query query); }查某一条数据Test public void testQueryOne(){ Account account jdbcTemplate.queryForObject(select * from account where name?, new BeanPropertyRowMapperAccount(Account.class), jerry); System.out.println(account account); }聚合查询用到的 (下面的SQL用于辅助回忆)查询全班总人数、总分、平均分、最高分、最低分SELECT COUNT(*) AS 总人数, SUM(score) AS 总分, AVG(score) AS 平均分, MAX(score) AS 最高分, MIN(score) AS 最低分 FROM student;// 聚合查询 Test public void testQueryAccount(){ Account account jdbcTemplate.queryForObject(select count(*) from account, Account.class); System.out.println(account account); }
返回列表