The error appears when an INSERT or UPDATE tries to store NULL in a column declared NOT NULL, violating the table’s integrity constraint.
“Column cannot be null” occurs when an INSERT or UPDATE supplies NULL to a NOT NULL column. Add a non-NULL value or alter the column to allow NULLs to resolve the issue.
ERROR 1048 (23000): Column 'column_name' cannot be null
MySQL raises Error 1048 when an INSERT or UPDATE statement puts a NULL into a column defined with a NOT NULL constraint. The engine halts execution to preserve data integrity.
This error is common in web apps, ETL jobs, and bulk imports where input validation is weak.
Fixing it quickly prevents orphaned rows, inconsistent reports, and application crashes.
Attempting to insert a row without assigning a value to a NOT NULL column triggers the violation immediately.
Program logic that converts empty strings, NaNs, or failed casts into NULL before persistence silently sets up the failure.
Foreign key inserts that rely on auto-increment values from a parent row may leave child rows with NULL references if the parent isn’t committed first.
Bulk loaders like LOAD DATA INFILE interpret specific tokens (\N) as NULL; malformed CSVs therefore break NOT NULL rules.
Supply a valid non-NULL value in the offending column or change the schema to permit NULLs when business rules allow.
Use DEFAULT clauses so the server auto-fills missing data, eliminating manual entry errors.
Re-order multi-table inserts or wrap them in transactions so foreign keys obtain real values before child rows save.
API receives blank JSON fields; sanitize input and map blanks to 0 or empty string instead of NULL.
CSV import lacks a value; preprocess the file or specify FIELDS OPTIONALLY ENCLOSED settings to handle empty strings.
ORM uses batched inserts; enable “defaults =true” so the library sends DEFAULT rather than NULL.
Enforce NOT NULL columns only where truly required; use CHECK constraints for richer validation.
Add application-side validation layers and CI tests to catch NULL payloads early.
Log failed statements with general_log or an APM tool, then fix the upstream data pipeline quickly.
Error 1364 “Field doesn’t have a default value” surfaces when a NOT NULL column lacks both a value and a DEFAULT.
Error 1452 “Cannot add or update child row: a foreign key constraint fails” appears when a NULL or invalid key is inserted into a foreign key field.
Oracle ORA-01400 and SQL Server Msg 515 are the platform-specific analogs of MySQL Error 1048.
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Yes. The server blocks NULL values in NOT NULL columns to maintain integrity. Correct the data or schema.
No. MySQL enforces NOT NULL at the storage-engine level; you must change each column explicitly.
Typically. A DEFAULT supplies non-NULL data when clients omit the column, preventing Error 1048.
Galaxy’s AI copilot warns when your draft query omits a NOT NULL column and suggests defaults, preventing runtime failures.
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