What Happens When MySQL DROP Permission Is Revoked? A Hands‑On Exploration

Background

A teammate mistakenly executed a DROP command on a production MySQL database, causing data loss. After the incident the operations team revoked the DROP privilege for the user hydra on all environments, prompting an investigation of how everyday SQL tasks behave without that permission.

1. Renaming a Table Without DROP

Attempting to rename a table using either ALTER TABLE … RENAME TO … or RENAME TABLE … TO … fails with the error:

1142 - DROP command denied to user 'hydra'@'localhost' for table 't_orders'

The MySQL documentation states that RENAME TABLE requires both ALTER and DROP privileges on the source table and CREATE and INSERT on the target table, explaining the failure.

2. TRUNCATE Becomes Unavailable

When the DROP privilege is missing, the TRUNCATE TABLE statement also cannot be executed. MySQL classifies TRUNCATE as a DDL operation that internally drops and recreates the table, which is why it requires the DROP privilege.

Using a plain DELETE FROM t_orders without a WHERE clause succeeds, but the auto‑increment counter is **not** reset. To reset it, an explicit ALTER TABLE t_orders AUTO_INCREMENT = 1; command is needed.

3. Scope of the DROP Command

Tests on various objects show the expected denial for databases, tables, and views:

DROP DATABASE mall;          -- Access denied (error 1044)
DROP TABLE t_orders;        -- DROP command denied (error 1142)
DROP VIEW order_view;       -- DROP command denied (error 1142)

Surprisingly, dropping a stored procedure succeeds even without DROP privilege because the privilege governing procedures is ALTER ROUTINE, not DROP. The official privilege matrix confirms this separation.

4. Recovering Data After a DELETE Using Binlog

Since TRUNCATE is unavailable, DELETE can be used to clear a table. To recover the deleted rows, the binary log must be enabled. Verify with: SHOW VARIABLES LIKE '%log_bin%'; If the result shows ON, the binlog is active. After executing DELETE FROM t_orders;, locate the relevant mysql-bin.* files in the data directory and identify the file covering the deletion time.

Copy the chosen binlog file to a temporary location and run mysqlbinlog to extract the statements:

mysqlbinlog --base64-output=decode-rows -v \
  --database=mall \
  --start-datetime="2021-09-17 20:50:00" \
  --stop-datetime="2021-09-17 21:30:00" \
  D:\tmp\mysql-bin.000001 > mysqllog.sql

The generated mysqllog.sql contains the original DELETE statements with row data, which can be transformed into INSERT statements (manually or via a script) to restore the lost records.

Conclusion

Revoking DROP privileges not only prevents accidental database deletions but also disables TRUNCATE and table‑renaming operations, while still allowing stored‑procedure removal. When DELETE is used for bulk clearing, the binary log provides a reliable recovery path, provided it is enabled and the appropriate time window is extracted.