sql语句中表前加入jeecg-boot-build是什么意思

Jeecg-boot-build是一种基于Jeecg-boot框架的代码生成器，它可以帮助开发者快速生成符合业务需求的代码。在SQL语句中，如果表名前加上jeecg-boot-build前缀，通常表示这个表是由Jeecg-boot-build生成的。这样做的目的是为了避免与用户手动创建的表名重复，同时也便于管理和维护。

相关问题

springboot整合ElasticsearchClient ，实现sql语句查询

要在Spring Boot应用程序中使用ElasticsearchClient进行SQL语句查询，需要以下步骤：

1. 添加ElasticsearchClient和其依赖项的Maven依赖关系：

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-client</artifactId>
    <version>7.9.3</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.9.3</version>
</dependency>

2. 配置ElasticsearchClient连接：

elasticsearch:
  rest:
    hosts: localhost:9200
    scheme: http

3. 创建ElasticsearchClient连接客户端：

import java.util.Collections;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.elasticsearch.RestClientProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.client.RestClients.ElasticsearchRestClient;
import org.springframework.data.elasticsearch.client.RestClients.ElasticsearchRestClientBuilder;
import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
import org.springframework.data.elasticsearch.core.convert.ElasticsearchConverter;
import org.springframework.data.elasticsearch.core.mapping.SimpleElasticsearchMappingContext;

@Configuration
public class ElasticsearchConfig {
    
    private final RestClientProperties properties;

    @Autowired
    public ElasticsearchConfig(RestClientProperties properties) {
        this.properties = properties;
    }

    @Bean
    public RestHighLevelClient elasticsearchClient() {
        return new ElasticsearchRestClientBuilder(Collections.singletonList(properties.getUris()))
            .withScheme(properties.getScheme())
            .withBasicAuth(properties.getUsername(), properties.getPassword())
            .build();
    }

    @Bean
    public ElasticsearchRestTemplate elasticsearchTemplate(RestHighLevelClient elasticsearchClient,
            ElasticsearchConverter elasticsearchConverter) {
        return new ElasticsearchRestTemplate(new ElasticsearchRestClient(elasticsearchClient), elasticsearchConverter);
    }

    @Bean
    public ElasticsearchConverter elasticsearchConverter() {
        return new ElasticsearchConverter(new SimpleElasticsearchMappingContext());
    }
}

4. 编写SQL查询，例如：

SELECT * FROM my_index WHERE title LIKE '%Spring%';

5. 在Spring Boot应用程序中使用ElasticsearchClient执行SQL查询：

import java.io.IOException;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.core.CountResponse;
import org.elasticsearch.client.core.SearchRequest;
import org.elasticsearch.client.core.SearchResponse;
import org.elasticsearch.client.core.TermVectorsRequest;
import org.elasticsearch.client.core.TermVectorsResponse;
import org.elasticsearch.client.sql.SqlRequest;
import org.elasticsearch.client.sql.SqlResponse;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.elasticsearch.client.RestClients.ElasticsearchRestClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class ElasticsearchController {

    @Autowired
    private ElasticsearchRestClient elasticsearchClient;

    @GetMapping("/search")
    public void search(@RequestParam("query") String query) throws IOException {
        SqlRequest sqlRequest = new SqlRequest(query);
        SqlResponse sqlResponse = elasticsearchClient.sql().query(sqlRequest).getResponse();
        System.out.println(sqlResponse.toString());
    }
}

spring boot sqlbuilder 实用实例

好的，下面是一个简单的Spring Boot SqlBuilder实用实例。

首先，需要在pom.xml文件中添加以下依赖：

<dependency>
    <groupId>org.mybatis.dynamic-sql</groupId>
    <artifactId>mybatis-dynamic-sql</artifactId>
    <version>1.2.0</version>
</dependency>

然后，在application.properties文件中配置数据库连接信息：

spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

接下来，创建一个User实体类：

public class User {
    private Long id;
    private String name;
    private Integer age;
    // 省略getter和setter方法
}

然后，创建一个UserMapper接口：

@Mapper
public interface UserMapper {
    @SelectProvider(type = SqlBuilder.class, method = "select")
    List<User> selectByExample(SelectStatementProvider selectStatement);
}

最后，创建一个UserService类：

@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
    public List<User> getUsers(String name, Integer age) {
        UserExample.Builder builder = UserExample.newBuilder();
        if (StringUtils.isNotBlank(name)) {
            builder.and(UserDynamicSqlSupport.name, isEqualTo(name));
        }
        if (age != null) {
            builder.and(UserDynamicSqlSupport.age, isEqualTo(age));
        }
        UserExample example = builder.build();
        return userMapper.selectByExample(example);
    }
}

在这个例子中，我们使用了MyBatis Dynamic SQL来构建SQL语句。UserExample是一个自动生成的类，它继承了GeneratedCriteria和AbstractGeneratedCriteria类，用于构建where条件。UserDynamicSqlSupport是另一个自动生成的类，它包含了User实体类中的所有字段，用于构建select语句中的列名。

在UserService类中，我们通过UserExample.Builder类构建了where条件，并将其传递给userMapper.selectByExample方法，从而执行查询操作。

这就是一个简单的Spring Boot SqlBuilder实用实例。