pg库也是常用的数据库之一，有些刚开始接触开发的老师可能不熟，这里简单介绍一下，总体使用方法和mysql类似，所以这里只讲配置方法

pom文件导入依赖

        <dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
        </dependency>        
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.18</version>
        </dependency>

yml文件配置(多数据源)：

spring:
  datasource:
    bd3:
      jdbc-url: jdbc:postgresql://XXX.XXX.XX.XXX:5432/test1?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&characterSetResults=utf8&useSSL=false&allowMultiQueries=true
      username: XXX
      password: XXX
      driver-class-name: org.postgresql.Driver
      type: com.zaxxer.hikari.HikariDataSource
      hikari:
        minimum-idle: 3
        auto-commit: true
        idle-timeout: 10000
        pool-name: DatebookHikariCP
        max-lifetime: 1800000
        connection-timeout: 30000
    timed:
      jdbc-url: jdbc:postgresql://XXX.XXX.XX.XXX:5432/test2?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&characterSetResults=utf8&useSSL=false&allowMultiQueries=true
      username: XXX
      password: XXX
      driver-class-name: org.postgresql.Driver
      type: com.zaxxer.hikari.HikariDataSource
      hikari:
        minimum-idle: 3
        auto-commit: true
        idle-timeout: 10000
        pool-name: DatebookHikariCP
        max-lifetime: 1800000
        connection-timeout: 30000

这个地方test1是数据库1，test2是数据库2，yml文件一定要主要好格式，建议用properties

下面是有关于多数据源的配置

文件夹格式，这里直接放贴图

不同数据源的dao层要放到对应文件夹下

下面是数据源的配置文件

MyBaitsSqlSessionFactory配置文件

package com.XXX.XXX.datasource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.boot.autoconfigure.SpringBootVFS;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;

import javax.sql.DataSource;

public class MyBaitsSqlSessionFactory {
    private MyBaitsSqlSessionFactory() {

    }

    private static final MyBaitsSqlSessionFactory onlyOne = new MyBaitsSqlSessionFactory();

    public static MyBaitsSqlSessionFactory getInstance() {
        return onlyOne;
    }

    public SqlSessionFactory sessionFactory(DataSource dataSource, String mapper_location, String type_aliases_package, boolean mapUnderscoreToCamelCase) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);

        bean.setVfs(SpringBootVFS.class);
        //mybatis扫描xml所在位置
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mapper_location));
        //实体类位置
        bean.setTypeAliasesPackage(type_aliases_package);
        //mybatis配置
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(mapUnderscoreToCamelCase);
        bean.setConfiguration(configuration);

        return bean.getObject();
    }

}

 

Bd3Config配置文件

package com.XXX.XXX.datasource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@SpringBootConfiguration
@MapperScan(basePackages = "com.XXX.XXX.dao.bd3", sqlSessionFactoryRef = "bd3SessionFactory", sqlSessionTemplateRef = "bd3SqlSessionTemplate")
public class Bd3Config {

    //@Value("${mybatis.mapper-locations}")
    private String mapper_location = "classpath*:/mapper/bd3/**/*.xml";

    @Value("${mybatis.type-aliases-package}")

    private String type_aliases_package;

    @Value("${mybatis.configuration.map-underscore-to-camel-case}")
    private boolean mapUnderscoreToCamelCase;

    /**
     * 初始化连接池
     *
     * @return DataSource
     */
    @Bean(name = "bd3")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.bd3")
    public DataSource bd3DataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 构建 SqlSessionFactory
     *
     * @return SqlSessionFactory
     */
    @Bean(name = "bd3SessionFactory")
    @Primary
    public SqlSessionFactory bd3SessionFactory() throws Exception {
        MyBaitsSqlSessionFactory myBatisFactory = MyBaitsSqlSessionFactory.getInstance();
        return myBatisFactory.sessionFactory(bd3DataSource(), mapper_location, type_aliases_package, mapUnderscoreToCamelCase);
    }

    /*
     * 配置事物
     *
     * @return DataSourceTransactionManager
     */
    @Bean("bd3TransactionManager")
    @Primary
    public DataSourceTransactionManager TransactionManager() {
        return new DataSourceTransactionManager(bd3DataSource());
    }

    /**
     * 构建 SqlSessionTemplate
     *
     * @return SqlSessionTemplate
     */
    @Bean(name = "bd3SqlSessionTemplate")
    @Primary
    public SqlSessionTemplate sqlSessionTemplate() throws Exception {
        return new SqlSessionTemplate(bd3SessionFactory());
    }
}

TimedConfig配置文件

package com.XXX.XXX.datasource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@SpringBootConfiguration
@MapperScan(basePackages = "com.XX.XXX.dao.timed", sqlSessionFactoryRef = "timedSessionFactory", sqlSessionTemplateRef = "timedSqlSessionTemplate")
public class TimedConfig {

    //@Value("${mybatis.mapper-locations}")
    private String mapper_location = "classpath*:/mapper/timed/**/*.xml";

    @Value("${mybatis.type-aliases-package}")

    private String type_aliases_package;

    @Value("${mybatis.configuration.map-underscore-to-camel-case}")
    private boolean mapUnderscoreToCamelCase;

    /**
     * 初始化连接池
     *
     * @return DataSource
     */
    @Bean(name = "timed")
    @ConfigurationProperties(prefix = "spring.datasource.timed")
    public DataSource timedDataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 构建 SqlSessionFactory
     *
     * @return SqlSessionFactory
     */
    @Bean(name = "timedSessionFactory")
    public SqlSessionFactory timedSessionFactory() throws Exception {
        MyBaitsSqlSessionFactory myBatisFactory = MyBaitsSqlSessionFactory.getInstance();
        return myBatisFactory.sessionFactory(timedDataSource(), mapper_location, type_aliases_package, mapUnderscoreToCamelCase);
    }

    /*
     * 配置事物
     *
     * @return DataSourceTransactionManager
     */
    @Bean("timedTransactionManager")
    public DataSourceTransactionManager TransactionManager() {
        return new DataSourceTransactionManager(timedDataSource());
    }

    /**
     * 构建 SqlSessionTemplate
     *
     * @return SqlSessionTemplate
     */
    @Bean(name = "timedSqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate() throws Exception {
        return new SqlSessionTemplate(timedSessionFactory());
    }
}

然后就可以正常使用了，希望大家技术越来越好！