<p>Raised when a WRITE lock is requested on a system table together with other tables or lock modes in the same LOCK TABLES statement.</p>
<p>MySQL Error 1428: ER_WRONG_LOCK_OF_SYSTEM_TABLE occurs when a WRITE lock is placed on a system table while other tables or lock types are included in the same LOCK TABLES statement. Issue separate LOCK TABLES calls or avoid WRITE locks on system tables to resolve the error.</p>
You can't combine write-locking of system tables with
MySQL throws Error 1428 with the message "You can't combine write-locking of system tables with other tables or lock types" when the LOCK TABLES statement includes a system table with a WRITE lock alongside any other table or lock mode. System tables include mysql.*, sys.*, performance_schema.*, and information_schema.*.
The server blocks this combination to protect critical metadata from deadlocks and corruption. Fixing it quickly is vital because the statement fails and any subsequent transactional logic depending on the lock sequence will also fail.
The error arises whenever a WRITE lock is requested on a system table in the same statement that also locks non-system tables or requests a different lock mode, such as READ. MySQL enforces single-table WRITE locks on its internal schemas to ensure metadata consistency.
It can also be triggered indirectly by stored procedures, backup scripts, or third-party tools that attempt broad WRITE locks for snapshot consistency.
Issue separate LOCK TABLES statements: first lock the required system table alone with WRITE, release it, then lock other tables as needed. Alternatively, switch to READ locks on system tables if writes are not required. In most cases, redesigning code to avoid modifying system tables is the safest fix.
When the goal is a consistent backup, use FLUSH TABLES WITH READ LOCK or the --single-transaction option of mysqldump instead of manual WRITE locks.
Backup scripts: Replace multiple WRITE locks with FLUSH TABLES WITH READ LOCK to take snapshots without halting DML activity.
Metadata migrations: Use dedicated maintenance windows and lock only the target system table, or rely on MySQL DDL statements that handle locking internally.
Avoid direct writes to mysql.* and sys.* tables. Use GRANT, REVOKE, and ALTER USER commands instead of manual updates. If you must lock, never combine a system table WRITE lock with other locks in the same statement.
Automate checks in CI to scan code for LOCK TABLES statements referencing system tables. Monitor error logs to catch lock failures early.
Galaxy's static analysis flags LOCK TABLES statements that target system tables with WRITE mode. The editor highlights the risky pattern and suggests splitting the locks. Collaborative review workflows help teams approve safe locking strategies before code reaches production.
Error 1100 - ER_TABLE_NOT_LOCKED: occurs when a session tries to access a table it has not locked. Resolve by adding the correct lock before access.
Error 1205 - Lock wait timeout exceeded: appears when a transaction waits too long for a lock. Tune innodb_lock_wait_timeout or redesign the transaction order.
Error 1550 - ER_LOCK_TABLE_FULL: raised when the lock table memory is exhausted. Free unused locks or increase the lock table size.
Requesting a WRITE lock on mysql.user while also requesting a READ lock on another table in the same LOCK TABLES call.
Including a system table such as performance_schema.threads with a WRITE lock and an application table like app.orders.
Legacy scripts that attempt to lock every table with WRITE to create a consistent backup snapshot.
Developers updating mysql.db directly and locking it with WRITE alongside other objects for convenience.
Raised when a session accesses a table without the required lock. Ensure the table is locked before access.
Occurs when a transaction waits too long for a lock. Reduce contention or increase the timeout.
Indicates the InnoDB lock table is full. Free locks or enlarge innodb_buffer_pool_size.
Yes, but only lock the single system table with WRITE in its own LOCK TABLES statement and keep the transaction short.
mysql, sys, performance_schema, and information_schema are regarded as system schemas for locking rules.
Not when run with --single-transaction. It uses transactional snapshots instead of WRITE locks on system tables.
Galaxy analyzes SQL in real time, flags risky LOCK TABLES patterns, and recommends safe alternatives, reducing production errors.
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