MySQL Error 1654: ER_WRONG_TYPE_COLUMN_VALUE_ERROR - How to Fix Partition Column Type Mismatch

What is MySQL Error 1654?

Error 1654 (SQLSTATE HY000) - ER_WRONG_TYPE_COLUMN_VALUE_ERROR - occurs when MySQL detects that a partition boundary value, list value, or partition selector is of a different data type than the partitioning column itself.

The server stops the statement because using mismatched types would corrupt partition metadata or return invalid rows.

What Causes This Error?

MySQL validates every partition value against the column types declared in PARTITION BY RANGE, LIST, HASH, or KEY. Supplying a string to an INT partition column, a numeric literal to a DATE column, or mixing signed and unsigned integers triggers the error.

The check happens during CREATE TABLE, ALTER TABLE, INSERT ... PARTITION, and SELECT ... PARTITION execution.

How to Fix MySQL Error 1654

First, confirm the data type of the partitioning column with DESCRIBE or INFORMATION_SCHEMA.COLUMNS. Next, rewrite partition values to the same type or use CAST. If the table already exists, ALTER TABLE ... REORGANIZE or REBUILD PARTITION with correct literals.

Common Scenarios and Solutions

CREATE TABLE statements often fail because developers quote numeric boundaries. SELECT ... PARTITION on a date-partitioned table fails when integers are passed instead of string dates. Bulk INSERT fails if the INSERT PARTITION clause lists partitions implicitly defined for another type.

Best Practices to Avoid This Error

Always store partition boundaries in constants of identical type. Script DDL with templates to reduce manual errors, and enable strict SQL mode to catch mismatches early.

Related Errors and Solutions

Errors 1503 (Partition constant out of range) and 1517 (Duplicate partition name) often surface during the same schema change. Align types first, then rebuild partitions to avoid a chain of related failures.