他报must appear in the group by clause or be used in an aggregate function错误

如果您使用以下语法：

SELECT COUNT(DISTINCT column_name), other_column_name FROM table_name;

则会出现“must appear in the GROUP BY clause or be used in an aggregate function”错误。这是因为在SELECT语句中，如果您使用了一个聚合函数，例如COUNT()，则所有未聚合的列都必须在GROUP BY子句中列出。因此，正确的语法如下所示：

SELECT COUNT(DISTINCT column_name), other_column_name FROM table_name GROUP BY other_column_name;

这将为每个不同的 other_column_name 值计算 column_name 的唯一值数量。

相关问题

must appear in the GROUP BY clause or be used in an aggregate function

This error message typically occurs in SQL when you are using a SELECT statement with GROUP BY but haven't included all the non-aggregated columns in the GROUP BY clause or used them in an aggregate function.

To fix this error, you have two options:

1. Include all non-aggregated columns in the GROUP BY clause: Make sure that all columns from the SELECT statement are either included in the GROUP BY clause or used in an aggregate function.

2. Use aggregate functions for non-aggregated columns: If including all non-aggregated columns in the GROUP BY clause is not feasible, you can use aggregate functions like SUM, COUNT, MAX, MIN, etc., for those columns instead.

Here's an example to illustrate the solutions:

-- Option 1: Include all non-aggregated columns in GROUP BY clause
SELECT column1, column2, SUM(column3)
FROM table
GROUP BY column1, column2;

-- Option 2: Use aggregate function for non-aggregated column
SELECT column1, column2, MAX(column3)
FROM table
GROUP BY column1, column2;

Remember to replace "column1", "column2", "column3", and "table" with your actual column names and table name.

column "b.person_name" must appear in the GROUP BY clause or be used in an aggregate function

这个错误意味着你在一个查询中使用了 GROUP BY 子句，但是列 "b.person_name" 没有在 GROUP BY 子句中出现，也没有被用于聚合函数。在 GROUP BY 子句中，你需要指定所有不在聚合函数中的列。

要解决这个问题，你可以将列 "b.person_name" 添加到 GROUP BY 子句中，或者在 SELECT 子句中使用聚合函数来处理它。例如，你可以这样修改查询：

SELECT b.person_name, COUNT(b.id)
FROM table_name b
GROUP BY b.person_name;

这样做将以 "person_name" 为分组依据，并计算每个组中的记录数量。请根据你的具体需求适当调整查询语句。