SpringBoot2通过sql脚本文件生成表时不成功

SpringBoot2通过jdbc生成数据表应该参看 DataSourceInitializerInvoker 这个类了

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 *
 * 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
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
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package org.springframework.boot.autoconfigure.jdbc;

import javax.sql.DataSource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationListener;

/**
 * Bean to handle {@link DataSource} initialization by running {@literal schema-*.sql} on
 * {@link InitializingBean#afterPropertiesSet()} and {@literal data-*.sql} SQL scripts on
 * a {@link DataSourceSchemaCreatedEvent}.
 *
 * @author Stephane Nicoll
 * @see DataSourceAutoConfiguration
 */
class DataSourceInitializerInvoker
        implements ApplicationListener<DataSourceSchemaCreatedEvent>, InitializingBean {

    private static final Log logger = LogFactory
            .getLog(DataSourceInitializerInvoker.class);

    private final ObjectProvider<DataSource> dataSource;

    private final DataSourceProperties properties;

    private final ApplicationContext applicationContext;

    private DataSourceInitializer dataSourceInitializer;

    private boolean initialized;

    DataSourceInitializerInvoker(ObjectProvider<DataSource> dataSource,
            DataSourceProperties properties, ApplicationContext applicationContext) {
        this.dataSource = dataSource;
        this.properties = properties;
        this.applicationContext = applicationContext;
    }

    @Override
    public void afterPropertiesSet() {
        DataSourceInitializer initializer = getDataSourceInitializer();
        if (initializer != null) {
            boolean schemaCreated = this.dataSourceInitializer.createSchema();
            if (schemaCreated) {
                initialize(initializer);
            }
        }
    }

    private void initialize(DataSourceInitializer initializer) {
        try {
            this.applicationContext.publishEvent(
                    new DataSourceSchemaCreatedEvent(initializer.getDataSource()));
            // The listener might not be registered yet, so don't rely on it.
            if (!this.initialized) {
                this.dataSourceInitializer.initSchema();
                this.initialized = true;
            }
        }
        catch (IllegalStateException ex) {
            logger.warn("Could not send event to complete DataSource initialization ("
                    + ex.getMessage() + ")");
        }
    }

    @Override
    public void onApplicationEvent(DataSourceSchemaCreatedEvent event) {
        // NOTE the event can happen more than once and
        // the event datasource is not used here
        DataSourceInitializer initializer = getDataSourceInitializer();
        if (!this.initialized && initializer != null) {
            initializer.initSchema();
            this.initialized = true;
        }
    }

    private DataSourceInitializer getDataSourceInitializer() {
        if (this.dataSourceInitializer == null) {
            DataSource ds = this.dataSource.getIfUnique();
            if (ds != null) {
                this.dataSourceInitializer = new DataSourceInitializer(ds,
                        this.properties, this.applicationContext);
            }
        }
        return this.dataSourceInitializer;
    }

}

 

SpringBoot2通过sql脚本文件生成表时不成功，控制台没有输出相关创建数据表的提示

在这篇博客找到了解决方法：https://blog.csdn.net/weixin_38306434/article/details/83379059

解决方法：（1） 在application配置文件指定执行sql（静态资源）的地方加上initialization-mode:always即可

                  （2）如果你配置文件没有指定执行文件的名称而是使用默认的schema.sql或者schema-all.sql的话就在配置文件中加上spring.datasource.initialization-mode=always

原理的话可能是这篇博客里面讲的：https://www.cnblogs.com/snoopy-GJT/p/10825019.html

因为SpringBoot在启动时，只有检测到spring.datasource.initialization-mode=ALWAYS配置，然后再检测spring.datasource.schema，且配置的sql角本命令不为空，才会去执行schema和spring.datasource.data。因此需要在scheme.sql中随便写一句sql语句。

所以在application.properties/application.yml文件中必须配置spring.datasource.initialization-mode=ALWAYS