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Groups work well in Oracle (provided that the fields of Group By are fixed, if not not not easy to use). By JDBC, when compiling SQL code, if the fields in Group are not fixed, but parameters, errors will be reported. If GROUP BY dynamic operation is really needed, there are two solutions: 1. Through SQL splicing, 2. Nested query nested que ...

Complete with JdbcTemplate method, query database tables, and return all data of user table sw_user to List < User > set. In the JdbcTemplateDemo class, add queryAllObject() to the method that queries return all sets of objects. Data source DriverManager Data Source remains unchanged The method of jdbcTemplate has changed, using query(sql ...

Configuration of XML methods through configuration files You can use a very concise Service class The UserService class code is as follows: package com.swift; public class UserService { private UserDao userDao; public void setUserDao(UserDao userDao) { this.userDao = userDao; } public boolean add() { return us ...

First, find the jar packages needed for IoC, aop and JdbcTemplate functions in the Spring framework. There are currently 13 Jar packages 1. Four core JAR packages in Spring Compression Pack to realize IoC control inversion and generate objects according to xml configuration files or annotations beans, context, core and expression Download addre ...

Using jdbcTemplate The principle is to load the driver Class.forName("com.mysql.jdbc.Driver"). Connect to the database Connection conn = DriverManager. getConnection ("jdbc: mysql://localhost: 3306/sw_database? User = root & password = root"); Complete DriverManagerDataSource dataSource=new DriverManagerDataSource() with ...

background mybatis is used only, but spring is not used because it involves multiple data sources, so each query uses the mapper factory method to create mappers to execute select or Update. Executor was closed when the same mapper executed select and executed update. Solve Log 2018-05-30 17:09:58,941 DEBUG [org.apache ...

Previously, when introducing the use of JdbcTemplate and Spring-data-jpa, single data sources were used. In the case of a single data source, the configuration of Spring Boot is very simple, just need to configure the connection parameters in the application.properties file. However, with the development of business, we usually split the databa ...

In the first two articles, we talked about two things: Getting started with spring boot through a simple example Modify the default service port number and context path of spring boot In this article, we'll look at how to persist data through JdbcTemplate. Don't talk too much nonsense, go straight to dry goods. I. Code Implementation Modify ...

Recently, in the process of development, we encountered the problem of using Transaction marked as rollback only. We learned the reasons for the error: It should be an error caused by multiple rollbacks of transactions. Looking at the code carefully, because the project has opened a transaction in aop aspect, contro ...

Using User as the Operating Object package com.swift.jdbc; public class User { private Long user_id; private String user_code; private String user_name; private String user_password; private String user_state; public User() { super(); // TODO Auto-generated constructor ...