# springboot的Crud

**Repository Path**: dddjjj1234/crud_of_springboot

## Basic Information

- **Project Name**: springboot的Crud
- **Description**: No description available
- **Primary Language**: Java
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2018-10-22
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

pom

  <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.15.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
  


    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>

    <dependency>
        <groupId>com.zaxxer</groupId>
        <artifactId>HikariCP</artifactId>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>6.0.5</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    
     </dependencies>
2.application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/mdstudent?useUnicode=true&characterEncoding=UTF-8&&serverTimezone=GMT%2B8&useSSL=false
spring.datasource.username=root
spring.datasource.password=123456

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.show-sql =true
server.port=80

3.DataSourceConfig

import com.zaxxer.hikari.HikariDataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;

import javax.sql.DataSource;

@Configuration
public class DataSourceConfig {
    @Bean("dataSource")
    public DataSource dataSource(Environment env){
        HikariDataSource ds=new HikariDataSource();
        ds.setJdbcUrl(env.getProperty("spring.datasource.url"));
        ds.setUsername(env.getProperty("spring.datasource.username"));
        ds.setPassword(env.getProperty("spring.datasource.password"));
        ds.setDriverClassName(env.getProperty("spring.datasource.driver-class-name"));
        return ds;
    }
}
4.主键生成策略

    @GeneratedValue(generator = "uuid2" )   //指定生成器名称
    @GenericGenerator(name = "uuid2", strategy = "org.hibernate.id.UUIDGenerator" )  //生成器名称，uuid生成类

5.字符串转日期

/** 
 * 将短时间格式字符串转换为时间 yyyy-MM-dd 
 *  
 * @param strDate 
 * @return 
 */  
public static Date strToDate(String strDate) {  
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");  
    ParsePosition pos = new ParsePosition(0);  
    Date strtodate = formatter.parse(strDate, pos);  
    return strtodate;  
}


6.mysql插入行数修改

...

1） 方法1

可以编辑my.cnf来修改（windows下my.ini）,在[mysqld]段或者mysql的server配置段进行修改。

max_allowed_packet = 20M

2） 方法2

进入mysql server

在mysql 命令行中运行

set global max_allowed_packet = 210241024*10

然后关闭掉这此mysql server链接，再进入。

show VARIABLES like '%max_allowed_packet%';

查看下max_allowed_packet是否编辑成功

...