📋

Description

This error signifies that an operation or function was attempted on a `NULL` value in a context where `NULL` is explicitly not permitted or logically makes no sense. It commonly arises during data manipulation, schema definition, or when query results unexpectedly yield `NULL`.

💬

Error Message

Invalid use of NULL value

🔍

Known Causes

4 known causes

⚠️

Violating NOT NULL Constraint

Attempting to insert or update a `NULL` value into a column that has been explicitly defined with a `NOT NULL` constraint.

⚠️

Function/Operator Expects Non-NULL

Using a `NULL` value as an argument for a SQL function or operator that requires a non-`NULL` input to perform its operation correctly.

⚠️

Incorrect Default Value Assignment

A `NULL` value is implicitly assigned where a non-`NULL` default was expected, or a `NULL` default value conflicts with a `NOT NULL` column definition.

⚠️

Subquery Returns NULL Unexpectedly

A subquery or expression that is expected to return a single non-`NULL` value instead returns `NULL`, leading to an invalid operation in the outer query.

🛠️

Solutions

4 solutions available

1. Identify and Correct NULL Constraints medium

Examine your table schema and application logic to ensure NULL values are not being inserted into columns that do not permit them.

1

Identify the table and column causing the error. The error message often provides context, or you can review recent `INSERT` or `UPDATE` statements.

2

Check the table schema for `NOT NULL` constraints on the offending column.

DESCRIBE your_table_name;

3

If a `NOT NULL` constraint is present, review your application's data insertion logic. Ensure that you are providing a valid, non-NULL value for this column. If the column is intended to allow NULLs, you may need to alter the table.

ALTER TABLE your_table_name MODIFY your_column_name DATATYPE NULL;

4

If the column should not be NULL, ensure your application code explicitly provides a value or a default value is set.

INSERT INTO your_table_name (column1, column2, your_column_name) VALUES ('value1', 'value2', 'non_null_value');

2. Provide Default Values for Columns easy

Define default values for columns that might otherwise receive NULL and cause this error.

1

Identify columns that are frequently involved in this error and are intended to have a sensible default value if not explicitly provided.

2

Alter the table to add a `DEFAULT` clause to the column definition. Choose an appropriate default value (e.g., 0 for numeric types, an empty string for text types, or a specific date/time).

ALTER TABLE your_table_name MODIFY your_column_name DATATYPE NOT NULL DEFAULT 'your_default_value';

3

When inserting data, if you omit the column, the default value will be used, preventing the NULL error.

INSERT INTO your_table_name (column1, column2) VALUES ('value1', 'value2');

3. Review Application Logic for NULL Handling medium

Inspect your application code that interacts with the database to ensure it correctly handles potential NULL values.

1

Examine your application's data access layer or ORM (Object-Relational Mapper) configuration. Look for instances where data is being fetched or processed, and then subsequently written back to the database.

2

Pay close attention to fields that are nullable in the database but might be represented as `None` (Python), `null` (JavaScript/Java), or similar in your programming language. Ensure these are either explicitly handled or mapped to appropriate database values.

Example (Python with SQLAlchemy):
if my_object.nullable_field is None:
    # Handle the None value, e.g., set a default or skip the update
    pass
else:
    # Proceed with saving the non-None value

3

If your application logic allows for optional fields that should not be NULL in the database, ensure that you are providing a default value or an empty string/zero where appropriate before sending the data to MariaDB.

4. Temporarily Allow NULLs for Data Migration or Cleanup easy

While not a permanent fix, this can be useful for resolving the error during large data imports or when cleaning up existing data.

1

Identify the table and column causing the issue.

2

Temporarily alter the table to allow NULL values for the specific column. This is a quick way to bypass the error during data loading or a cleanup operation.

ALTER TABLE your_table_name MODIFY your_column_name DATATYPE NULL;

3

Once the data is loaded or cleaned up, you should ideally revert the change or ensure all NULLs are replaced with valid data. If the column should truly be `NOT NULL`, you'll need to address the data itself.

ALTER TABLE your_table_name MODIFY your_column_name DATATYPE NOT NULL DEFAULT 'some_value';

🔗

Related Errors

5 related errors

MariaDB Error 1138: Invalid NULL Usage