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9 Ιουν 2011 · delete from YourTable where YourTable.columnA in (select columnA from YourTable group by column A having count(*) > 1)
The GROUP BY statement groups rows that have the same values into summary rows, like "find the number of customers in each country". The GROUP BY statement is often used with aggregate functions ( COUNT() , MAX() , MIN() , SUM() , AVG() ) to group the result-set by one or more columns.
16 Απρ 2024 · Deleting a MySQL user removes the user's account and the associated grant table privileges. Only admins with global CREATE USER or DELETE privileges can remove another user from MySQL. In this tutorial, learn how to remove one or more MySQL user accounts using the DROP USER statement.
4 Απρ 2021 · DELETE t1 FROM data t1 JOIN data t2 USING (channel_id,timestamp) WHERE t1.id > t2.id
The DELETE statement deletes rows from tbl_name and returns the number of deleted rows. To check the number of deleted rows, call the ROW_COUNT() function described in Section 14.15, “Information Functions”. Main Clauses. The conditions in the optional WHERE clause identify which rows to delete.
Example 2: Delete Multiple Rows Based on a Condition. To delete multiple rows, specify a condition that matches several records. For example, to delete all students with an age of 20: WHERE age = 20; This command deletes all rows where age is 20, which will remove both “Sai” and any other students with that age.
The DELETE statement deletes rows from tbl_name and returns the number of deleted rows. To check the number of deleted rows, call the ROW_COUNT() function described in Section 14.15, “Information Functions”. Main Clauses. The conditions in the optional WHERE clause identify which rows to delete.
