技術標籤：mysql

1.問題發生

問題

1055 - Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'reporter.reporter_status.N_APP_CODE' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

字面意思

this is incompatible with sql_mode=only_full_group_by

1055 - Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'reporter.reporter_status.N_APP_CODE' which is not functionally dependent on columns in GROUP BY clause
選擇列表的表示式#2不在GROUP BY子句中，並且包含非聚合列的reporter_status。N_APP_CODE'，它在功能上不依賴於GROUP BY子句中的列;

問題發生的語句

select id,count(*),an
from tb4
group by id

2.問題解決

2.1問題分析

資料來源

問題原因：id為1的分組裡面出現了兩個an（1和4）。所以出現了選擇的問題。

2.2 解決方案：

方案1.為查找出的發生碰撞的欄位加上any_value函式，於是就成了下面這種

select id,count(*),any_value(an)
from tb4
group by id

結果

方案2 設定sql_mode

2.1 獲取 @@sql_mode

select @@sql_mode

結果如下，這裡的ONLY_FULL_GROUP_BY就是要刪除的模式

ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

2.2 設定@@sql_mode（有兩種方法）

長效

SET GLOBAL sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';

臨時有效 (重啟後會失效)

SET SESSION sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';

方案3.設定配置檔案（在my.ini檔案中追加如下配置）

sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION