Is there a field after select?

Yes, the field SELECT must be followed by GROUP BY. Because GROUP BY is used for grouping and SELECT is used to select the columns to be returned, the GROUP BY query must contain an aggregate function and a grouped column.

Group By field Select must be followed by?

Answer: Yes, there must be.

Expand the answer:

The GROUP BY clause is used to group records in a dataset and aggregate them together by the values ​​of some columns. The column specified in the GROUP BY clause is called a grouped column.

The SELECT clause is used to select the column to return from the table. In a GROUP BY query, the SELECT clause must contain the following:

• Aggregation function: Used to aggregate values ​​of grouped columns, such as SUM, COUNT, or AVG.
• Grouped column: Specifies the column to group the dataset.

If the SELECT clause does not contain an aggregate function or grouped column, the query will be invalid.

Example:

The following query groups the departments in the employee table and calculates the number of employees in each department:

 <code class="sql">SELECT department, COUNT(*) AS employee_count FROM employees GROUP BY department;</code>

In this query:

• department is grouped column
• COUNT(*) is an aggregate function that calculates the number of employees in each department

If there is no COUNT(*) aggregate function or department grouping column, the query will be invalid.

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