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Description

This error occurs when a SQL query attempts to select both aggregate functions (e.g., MIN(), MAX(), COUNT()) and non-aggregated columns without providing a GROUP BY clause. MySQL requires a clear grouping strategy to process such queries, as it cannot determine how to group the non-aggregated data.

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Error Message

Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause

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Known Causes

3 known causes

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Omitted GROUP BY Clause

The most common cause is simply forgetting to include a GROUP BY clause when using aggregate functions alongside non-aggregated columns.

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Incomplete GROUP BY Columns

The GROUP BY clause might be present but does not include all the non-aggregated columns from the SELECT list, leading to ambiguity.

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Misunderstanding Aggregate Logic

Developers might not fully understand how aggregate functions interact with non-aggregate columns, assuming implicit grouping.

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Solutions

4 solutions available

1. Add a GROUP BY Clause easy

Explicitly define how to group rows when using aggregate functions.

1

Identify the columns you intend to group by. These are typically non-aggregated columns present in your SELECT list.

2

Append a `GROUP BY` clause to your SQL query, listing the identified columns.

SELECT column1, COUNT(column2) FROM your_table WHERE condition GROUP BY column1;

2. Remove Aggregate Functions Without GROUP BY easy

Eliminate aggregate functions if you don't intend to group rows.

1

Review your `SELECT` statement for any aggregate functions (e.g., `MIN()`, `MAX()`, `COUNT()`, `SUM()`, `AVG()`).

2

If you do not want to aggregate data, remove these aggregate functions from your `SELECT` list. Ensure all selected columns are directly present in the table or derived without aggregation.

SELECT column1, column2 FROM your_table WHERE condition;

3. Use Aggregate Functions on All Non-Grouped Columns medium

Apply an aggregate function to every column that isn't part of the GROUP BY clause.

1

Determine which columns you want to aggregate (e.g., using `COUNT()`, `SUM()`) and which columns you want to group by.

2

For any column in the `SELECT` list that is *not* in the `GROUP BY` clause, wrap it in an appropriate aggregate function. This ensures consistency.

SELECT column1, MIN(column2), MAX(column3) FROM your_table WHERE condition GROUP BY column1;

4. Modify Query to Select Only Non-Aggregated Columns easy

Ensure all selected columns are either non-aggregated or explicitly grouped.

1

Examine your `SELECT` statement. If you are not using a `GROUP BY` clause, all columns in the `SELECT` list must be non-aggregated. This means they should be regular column names, not results of functions like `COUNT()`, `SUM()`, etc.

2

If you intended to use aggregate functions, either add a `GROUP BY` clause (Solution 1) or remove the aggregate functions if you want to see individual row details (Solution 2). If you intended to get a single aggregated value for the entire table, ensure only aggregate functions are in the SELECT list (and no `GROUP BY` is needed).

SELECT COUNT(*) FROM your_table WHERE condition;

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Related Errors

5 related errors

MySQL Error 1140: Mixed Grouping Columns