Springboot（二十）启动时数据库初始化spring.datasource/spring.jpa

绝地灬酷狼 2022-05-15 06:47 323阅读 0赞

### 1.使用springboot jdbc初始化数据库 ###

spring:
      datasource:
        username: xuhaixing
        password: xuhaixing
        url: jdbc:mysql://192.168.94.151:3306/mytest?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8
        driver-class-name: com.mysql.jdbc.Driver
        platform: mysql
        #启动时需要初始化的建表语句
        schema: classpath:schema-mysql.sql
        #初始化的数据
        data: classpath:data-mysql.sql
        # Initialize the datasource with available DDL and DML scripts.
        initialization-mode: always
        continue-on-error: false
        #data-password:
        #data-username:
        #schema-password:
        #schema-username:
        sql-script-encoding: utf-8
        separator: ;

spring.datasource下有两个属性  schme、data，其中schema为表初始化语句，data为数据初始化，默认加载schema.sql与data.sql。脚本位置可以通过spring.datasource.schema  与spring.datasource.data 来改变，源码如下：

/**
    	 * Create the schema if necessary.
    	 * @return {@code true} if the schema was created
    	 * @see DataSourceProperties#getSchema()
    	 */
    	public boolean createSchema() {
    		List<Resource> scripts = getScripts("spring.datasource.schema",
    				this.properties.getSchema(), "schema");
    		if (!scripts.isEmpty()) {
    			if (!isEnabled()) {
    				logger.debug("Initialization disabled (not running DDL scripts)");
    				return false;
    			}
    			String username = this.properties.getSchemaUsername();
    			String password = this.properties.getSchemaPassword();
    			runScripts(scripts, username, password);
    		}
    		return !scripts.isEmpty();
    	}
    
    	/**
    	 * Initialize the schema if necessary.
    	 * @see DataSourceProperties#getData()
    	 */
    	public void initSchema() {
    		List<Resource> scripts = getScripts("spring.datasource.data",
    				this.properties.getData(), "data");
    		if (!scripts.isEmpty()) {
    			if (!isEnabled()) {
    				logger.debug("Initialization disabled (not running data scripts)");
    				return;
    			}
    			String username = this.properties.getDataUsername();
    			String password = this.properties.getDataPassword();
    			runScripts(scripts, username, password);
    		}
    	}

看getScripts源码，它还会加载schema-$\{platform\}.sql文件，或者data-$\{platform\}.sql文件，其中platform就是spring.datasource.platform的值

private List<Resource> getScripts(String propertyName, List<String> resources,
    			String fallback) {
    		if (resources != null) {
    			return getResources(propertyName, resources, true);
    		}
    		String platform = this.properties.getPlatform();
    		List<String> fallbackResources = new ArrayList<>();
    		fallbackResources.add("classpath*:" + fallback + "-" + platform + ".sql");
    		fallbackResources.add("classpath*:" + fallback + ".sql");
    		return getResources(propertyName, fallbackResources, false);
    	}

spring.datasource.initialization-mode  初始化模式（springboot2.0），其中有三个值，always为始终执行初始化，embedded只初始化内存数据库（默认值）,如h2等，never为不执行初始化。

/*
     * Copyright 2012-2017 the original author or authors.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *      http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    
    package org.springframework.boot.jdbc;
    
    /**
     * Supported {@link javax.sql.DataSource} initialization modes.
     *
     * @author Vedran Pavic
     * @author Stephane Nicoll
     * @since 2.0.0
     * @see AbstractDataSourceInitializer
     */
    public enum DataSourceInitializationMode {
    
    	/**
    	 * Always initialize the datasource.
    	 */
    	ALWAYS,
    
    	/**
    	 * Only initialize an embedded datasource.
    	 */
    	EMBEDDED,
    
    	/**
    	 * Do not initialize the datasource.
    	 */
    	NEVER
    
    }

spring.datasouce.data-passwork:

spring.datasouce.data-username:

spring.datasouce.schema-password:

spring.datasouce.schema-username:

这四个值为执行schema.sql或者data.sql时，用的用户

spring.datasource.sql-script-encoding: utf-8 为文件的编码

spring.datasource.separator: ; 为sql脚本中语句分隔符

spring.datasource.continue-on-error: false   遇到语句错误时是否继续，若已经执行过某些语句，再执行可能会报错，可以忽略，不会影响程序启动

2.使用hibernate初始化数据库

spring:
      jpa:
        show-sql: true
        #启动时是否初始化数据库-hibernate
        generate-ddl: false
        hibernate:
          ddl-auto: update

generate-ddl: 为true时，执行schema创建，会检测classpath下的import.sql文件，当然spring.jpa.hibernate.ddl-auto: 必须为create/update/create-drop，none和validate是不行的，因为这个创建时hibernate的，所以建议用spring的

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[20190217164104853.jpg]: /images/20220515/2552191ef70c40cfa4dc743abb452db8.png