sql查询一个字段多列值合并为一列sql 多列合并成一列查询多列合并一列，group by合并一列查询，多列数据

女爷i 2023-01-06 11:44 196阅读 0赞

# 1、针对1对多，查询合并多列的情况场景解决方案： #

SELECT
    	t.news_id,
    	t.sentiment_label AS '情感', ( 
    CASE WHEN    t.sentiment_label=1
    then '负面'
    WHEN    t.sentiment_label=2
    then '中性'
    ELSE   '正面'
    END
    ) as  '情感描述'
    FROM
    	tbm_popular_feelings t
    WHERE
    	t.sentiment_label IS NOT NULL
    AND t.create_time BETWEEN '2021-01-10 09:55:00'
    AND '2021-01-14 09:55:00'
    ORDER BY   t.id  desc;

运行结果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk_size_16_color_FFFFFF_t_70][]

# 2、合并结果，多列为一列： #

运行的SQL语句：

关键字：

**    GROUP\_CONCAT(t.sentiment\_label) AS '情感'**

SELECT
    		t.news_id,
    			GROUP_CONCAT(t.sentiment_label) AS '情感'
    	FROM
    		tbm_popular_feelings t
    	WHERE
    		t.sentiment_label IS NOT NULL
    	AND t.create_time BETWEEN '2021-01-10 09:55:00'
    	AND '2021-01-14 09:55:00'
     GROUP BY
     t.news_id;

运行结果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk_size_16_color_FFFFFF_t_70 1][]

# 3、进行编码枚举描述说明，进一步优化SQL显示结果更为友好： #

SELECT
    	t.news_id,
    	GROUP_CONCAT(t.sentiment_label) AS '情感',
    	GROUP_CONCAT(
    		CASE
    		WHEN t.sentiment_label = 1 THEN
    			'负面'
    		WHEN t.sentiment_label = 2 THEN
    			'中性'
    		ELSE
    			'正面'
    		END
    	) AS '情感描述'
    FROM
    	tbm_popular_feelings t
    WHERE
    	t.sentiment_label IS NOT NULL
    AND t.create_time BETWEEN '2021-01-10 09:55:00'
    AND '2021-01-14 09:55:00'
    GROUP BY
    	t.news_id;

运行结果如下：

看起来更为友好！

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk_size_16_color_FFFFFF_t_70 2][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk_size_16_color_FFFFFF_t_70]: /images/20221119/a58213e63a10496a8a81ab0cfaf02628.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20210114141825427.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20210114142534621.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0ODgwMDk=,size_16,color_FFFFFF,t_70