📋

Description

This error occurs when a `CREATE TABLE` or `ALTER TABLE` statement attempts to define an `ON UPDATE` clause for a column using a data type or syntax that MySQL does not support. It commonly happens when trying to automatically update a column's value upon row modification, preventing the table definition from being applied.

💬

Error Message

Invalid ON UPDATE clause for '%s' column

🔍

Known Causes

3 known causes

⚠️

Incorrect Data Type for ON UPDATE

Applying `ON UPDATE CURRENT_TIMESTAMP` to a column that is not of `TIMESTAMP` or `DATETIME` type. MySQL restricts this automatic update behavior to specific temporal types.

⚠️

Unsupported ON UPDATE Expression

Specifying an expression other than `CURRENT_TIMESTAMP` (or its synonyms like `NOW()`) within the `ON UPDATE` clause, which is not permitted for automatic column updates.

⚠️

Multiple ON UPDATE CURRENT_TIMESTAMP Columns

Attempting to define more than one `TIMESTAMP` or `DATETIME` column with `ON UPDATE CURRENT_TIMESTAMP` in a single table, which certain MySQL versions or configurations do not allow.

🛠️

Solutions

3 solutions available

1. Remove Invalid ON UPDATE Clause easy

Directly remove the problematic ON UPDATE clause from the column definition.

1

Identify the column causing the error. The error message usually indicates the column name (e.g., '%s' in the error message).

2

Modify the table definition to remove the invalid `ON UPDATE` clause. For example, if the column is `updated_at` and it has an invalid `ON UPDATE` clause, change its definition.

ALTER TABLE your_table_name MODIFY COLUMN your_column_name DATETIME;

3

If the column was intended to be automatically updated, consider using a valid `ON UPDATE` clause such as `CURRENT_TIMESTAMP` if the column type supports it and you are using a compatible MySQL version.

ALTER TABLE your_table_name MODIFY COLUMN your_column_name DATETIME ON UPDATE CURRENT_TIMESTAMP;

2. Correct ON UPDATE Clause Syntax medium

Ensure the ON UPDATE clause uses a valid value or function compatible with the column type and MySQL version.

1

Review the `ON UPDATE` clause for the specified column. Common valid values include `CURRENT_TIMESTAMP` for timestamp-related data types.

2

If the column is a `DATETIME` or `TIMESTAMP`, and you want it to update automatically when the row is modified, use `CURRENT_TIMESTAMP`.

ALTER TABLE your_table_name MODIFY COLUMN your_column_name DATETIME ON UPDATE CURRENT_TIMESTAMP;

3

If the `ON UPDATE` clause is referencing a specific value or a function that is not supported or incorrectly specified, correct it to a valid MySQL expression. For example, you cannot use a user-defined function directly in `ON UPDATE` in older MySQL versions without specific configurations.

3. Define a Trigger for Complex Updates advanced

Use a trigger for more complex update logic that cannot be handled by a simple ON UPDATE clause.

1

Identify the column and the desired update logic that is not supported by a direct `ON UPDATE` clause.

2

Create a `BEFORE UPDATE` trigger for the table.

CREATE TRIGGER trigger_name
BEFORE UPDATE ON your_table_name
FOR EACH ROW
BEGIN
  -- Your custom update logic here
  SET NEW.your_column_name = your_desired_value_or_expression;
END;

3

Ensure the trigger logic correctly sets the `NEW.your_column_name` to the desired value. This approach offers maximum flexibility.

4

Remove any invalid `ON UPDATE` clause from the column definition in the table schema.

ALTER TABLE your_table_name MODIFY COLUMN your_column_name DATETIME;

🔗

Related Errors

5 related errors

MySQL Error 1294: Invalid ON UPDATE Clause