jdbctemplate

How to get Map data using JDBCTemplate.queryForMap

回眸只為那壹抹淺笑 提交于 2019-11-28 19:47:56
问题 How to load data from JDBCTemplate.queryForMap() and it returns the Map Interface.How the maintained the query data internally in map.I trying to load but i got below exception i.e., org.springframework.dao.IncorrectResultSizeDataAccessException: Incorrect result Code:- public List getUserInfoByAlll() { List profilelist=new ArrayList(); Map m=new HashMap(); m=this.jdbctemplate.queryForMap("SELECT userid,username FROM USER"); Set s=m.keySet(); Iterator it=s.iterator(); while(it.hasNext()){

Spring's JdbcTemplate and Transactions

百般思念 提交于 2019-11-28 19:28:37
When using JdbcTemplate, do I need to explicitly configure transactions? My code layout looks like the following: I will have a UserDao that will be injected into my UserService, and then my Controllers will make calls on methods in my UserService. I want to keep things as simple as possible transaction wise, and I don't need multiple database calls to span a transaction. By default, do I have to do anything in my configuration file or use a @Transaction annotation anywhere? Now say in my controller I need to make 2 calls on my userService and accountService, could I explicitly wrap it in a

using Spring JdbcTemplate - injecting datasource vs jdbcTemplate

泄露秘密 提交于 2019-11-28 18:12:23
As per Spring documentation , the steps to use Spring JdbcTemplate is as follows: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <!-- Scans within the base package of the application for

JDBC_Template(简化代码)

爱⌒轻易说出口 提交于 2019-11-28 17:47:51
1 /** 2 * @Description: TODO(这里用一句话描述这个类的作用) 3 * @Author aikang 4 * @Date 2019/8/27 11:03 5 */ 6 /* 7 Spring JDBC: 8 Spring框架队JDBC的简单封装,提供了一个JDBCTemplate对象简化JDBC的开发 9 步骤: 10 1.导入5个jar包 11 2.创建JDBCTemplate对象,依赖于数据源DataSource 12 JDBCTemplate template = new JdbcTemplate(ds); 13 3.调用JdbcTemplate的方法来完成CRUD的操作 14 update():执行DML语句,增删改 15 queryForMap():查询结果将结果集封装为map集合 16 queryForList():查询结果将结果集封装为list集合 17 query(sql,RowMapper接口 ):查询结果,将结果封装为JavaBean对象 18 常用实现类(new BeanPropertyRowMapper<Emp>(emp.class)), 19 20 queryForObject(sql,结果类型.class):查询结果,将结果封装为对象 21 JdbcTemplate入门: 22 1.导入jar包 23 2

Spring JDBCTemplate VS Hibernate in terms of performance [closed]

情到浓时终转凉″ 提交于 2019-11-28 15:07:57
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed last year . In our project we have to decide between Spring JDBCTemplate and Hibernate. I want to know which is better in terms of performance and implementation and design. and how? 回答1: If you do all you can to make both implementations very fast, the JDBC template will probably be a bit faster, because it doesn't have the

业务层框架spring(3)

余生长醉 提交于 2019-11-28 12:54:39
原文引用 https://www.dazhuanlan.com/2019/08/25/5d6220cfd6c0c/ JDBC JDBCTemplate 数据库 配置文档 pojo Dao Test 具名参数 JDBC JDBCTemplate 为了使 JDBC 更加易于使用, Spring 在 JDBC API 上定义了一个抽象层, 以此建立一个 JDBC 存取框架 JdbcTemplate 类被设计成为线程安全的,所以可以再 IOC 容器中声明它的单个实例, 并将这个实例注入到所有的 DAO 实例中 JdbcTemplate 也利用了 Java 1.5 的特定(自动装箱, 泛型, 可变长度等)来简化开发 Spring JDBC 框架还提供了一个 JdbcDaoSupport 类来简化 DAO 实现. 该类声明了 jdbcTemplate 属性, 它可以从 IOC 容器中注入, 或者自动从数据源中创建 数据库 db.properties jdbc.user=root jdbc.password=1230 jdbc.driverClass=com.mysql.jdbc.Driver jdbc.jdbcUrl=jdbc:mysql:///spring jdbc.initPoolSize=5 jdbc.maxPoolSize=10 配置文档 ApplicationContext.xml

spring中的JdbcTemplate简单记录

寵の児 提交于 2019-11-28 10:27:03
JdbcTemplate主要提供以下五类方法: execute方法: 可以用于执行任何SQL语句,一般用于执行DDL语句; update方法及batchUpdate方法: update方法用于执行新增、修改、删除等语句;batchUpdate方法用于执行批处理相关语句; query方法及queryForXXX方法: 用于执行查询相关语句; call方法: 用于执行存储过程、函数相关语句。 JdbcTemplate类支持的回调类: 预编译语句及存储过程创建回调: 用于根据JdbcTemplate提供的连接创建相应的语句; PreparedStatementCreator :通过回调获取JdbcTemplate提供的Connection,由用户使用该Conncetion创建相关的PreparedStatement; CallableStatementCreator: 通过回调获取JdbcTemplate提供的Connection,由用户使用该Conncetion创建相关的CallableStatement; 预编译语句设值回调: 用于给预编译语句相应参数设值; PreparedStatementSetter: 通过回调获取JdbcTemplate提供的PreparedStatement,由用户来对相应的预编译语句相应参数设值; BatchPreparedStatementSetter:

multiple one-to-many relations ResultSetExtractor

喜夏-厌秋 提交于 2019-11-28 06:06:35
Let's say I have an object with two different one-to-many relations. Much like: Customer 1<->M Brands and Customer 1<->M Orders And let's say that the my object Customer has two lists related to those two objects. I've read this example: http://forum.springsource.org/showthread.php?50617-rowmapper-with-one-to-many-query which explains how to do it with a single one-to-many relationship. For your convenience here's the ResultSetExtractor override: private class MyObjectExtractor implements ResultSetExtractor{ public Object extractData(ResultSet rs) throws SQLException, DataAccessException { Map

Spring boot - how to configure multiple datasources

≯℡__Kan透↙ 提交于 2019-11-28 05:57:15
问题 I am trying to setup multiple data sources(MySql, Postgres & Oracle) using Spring boot. I am not using JPA. Setting up with a JdbcTemplate. I have tried setting up something like this. application.properties spring.datasource.test-oracle.username=test-oracle spring.datasource.test-oracle.password=test-password spring.datasource.test-oracle.url=dburl/test spring.datasource.test-oracle.driver-class-name=oracle.jdbc.OracleDriver spring.datasource.int-oracle.username=int-oracle spring.datasource

Spring JdbcTemplate&声明式事务

时间秒杀一切 提交于 2019-11-28 05:52:36
1、JdbcTemplate基本使用 1)、JdbcTemplate基本使用-概述(了解) JdbcTemplate是spring框架中提供的一个对象,是对原始繁琐的Jdbc API对象的简单封装。spring框架为我们提供了很多的操作模板类。例如:操作关系型数据的JdbcTemplate和HibernateTemplate,操作nosql数据库的RedisTemplate,操作消息队列的JmsTemplate等等。 2)、JdbcTemplate基本使用-开发步骤(理解) ①导入spring-jdbc和spring-tx(事务)坐标 ②创建数据库表和实体 ③创建JdbcTemplate对象 设置连接池 ④执行数据库操作 3)、JdbcTemplate基本使用-快速入门代码实现(应用) ①导入Spring-jdbc和Spring-tx坐标(依赖) <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.0.5.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId