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Description

This error occurs when an ALTER statement attempts an operation that MySQL does not support for the specified database object or context. It typically arises when trying to modify a table, column, or index with an unsupported attribute change or a disallowed data type conversion.

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Error Message

%s is not supported for this operation. Try %s.

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Known Causes

3 known causes

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Unsupported Column Type Change

You attempted to change a column's data type to one not supported for direct conversion or by the current table definition.

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Invalid Index Definition

The ALTER statement tried to create or modify an index with an unsupported type, algorithm, or on an incompatible column.

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Disallowed Table or Partition Option

An ALTER TABLE statement included an option (e.g., ROW_FORMAT, COMPRESSION) not supported by the table's storage engine or MySQL version.

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Solutions

3 solutions available

1. Recreate Table with Desired Schema medium

Create a new table with the correct schema and copy data over.

1

Identify the unsupported operation and the alternative suggested by the error message.

2

Create a new table with the desired schema, incorporating the suggested change or a valid alternative.

CREATE TABLE new_table_name LIKE original_table_name;
ALTER TABLE new_table_name MODIFY COLUMN column_name new_data_type [constraints];

3

Copy all data from the original table to the new table.

INSERT INTO new_table_name SELECT * FROM original_table_name;

4

Verify the data integrity and schema of the new table.

DESCRIBE new_table_name;
SELECT COUNT(*) FROM new_table_name;

5

Rename the tables to replace the original with the new one. Ensure you handle foreign key constraints and indexes if necessary.

DROP TABLE original_table_name;
RENAME TABLE new_table_name TO original_table_name;

2. Perform Operations in Stages medium

Break down complex ALTER operations into simpler, supported steps.

1

Analyze the `ALTER TABLE` statement and identify the specific operation causing the error.

2

If the error is due to modifying a column type that cannot be directly altered, first change the column to a compatible type, then perform the final desired type change. For example, if changing from `TEXT` to `VARCHAR` directly is unsupported, you might first change it to a larger `VARCHAR` or `BLOB`.

ALTER TABLE your_table MODIFY COLUMN your_column VARCHAR(255);
-- Then, if needed:
ALTER TABLE your_table MODIFY COLUMN your_column VARCHAR(100);

3

If the error involves adding/dropping a column that has dependencies (like being part of an index or foreign key), first drop the dependency, then perform the column operation, and finally recreate the dependency.

ALTER TABLE your_table DROP INDEX index_name;
ALTER TABLE your_table DROP COLUMN your_column;
ALTER TABLE your_table ADD COLUMN your_column new_data_type;
ALTER TABLE your_table ADD INDEX index_name (your_column);

4

Test each intermediate step to ensure it's successful before proceeding to the next.

3. Check MySQL Version and Storage Engine Compatibility easy

Ensure your MySQL version supports the intended ALTER operation and that the storage engine is compatible.

1

Determine your current MySQL server version.

SELECT VERSION();

2

Identify the storage engine of the table you are trying to alter.

SHOW CREATE TABLE your_table_name;

3

Consult the MySQL documentation for your specific version to verify if the `ALTER TABLE` operation you are attempting is supported for your table's storage engine (e.g., InnoDB, MyISAM). Some operations might be restricted or require specific configurations for certain engines.

4

If the operation is not supported or is known to be problematic with your current configuration, consider upgrading your MySQL server to a newer version that offers better support for such operations. Alternatively, if possible and appropriate, convert your table to a storage engine that better supports the desired `ALTER TABLE` operation (e.g., InnoDB is generally more feature-rich for online DDL compared to MyISAM).

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Related Errors

5 related errors

MySQL Error 1845: Unsupported ALTER Operation