MySQL Error 1090: ER_CANT_REMOVE_ALL_FIELDS – How to Fix “You can't delete all columns with ALTER TABLE”

What is MySQL Error 1090 (ER_CANT_REMOVE_ALL_FIELDS)?<\/h2>Error 1090 — ER_CANT_REMOVE_ALL_FIELDS — is raised when MySQL detects an ALTER TABLE command that removes every column in the target table.<\/p>

The server prevents the operation because a table with zero columns cannot store data or metadata.

Instead, MySQL expects you to drop the whole table or leave at least one column alive.<\/p>

What Causes This Error?<\/h3>The primary cause is an ALTER TABLE … DROP COLUMN statement that lists every existing column, either explicitly or through a generated script.<\/p>

The error can also surface when a migration tool produces incremental ALTER TABLE commands that, together, remove all columns in a single batch.<\/p>

How to Fix MySQL Error 1090<\/h3>Replace ALTER TABLE … DROP COLUMN syntax with DROP TABLE if you truly intend to discard the table entirely.<\/p>

When only a schema redesign is needed, keep at least one column — usually the primary key or an audit column — then add new columns as required.<\/p>

Common Scenarios and Solutions<\/h3>Schema migrations often consolidate multiple DROP COLUMN statements.

Reorder the migration so that new columns are added before old ones are dropped.<\/p>

Infrastructure-as-code tools may generate an empty table as an intermediary step. Configure the tool to use CREATE TABLE … AS SELECT or temp tables to avoid the all-drop pattern.<\/p>

Best Practices to Avoid This Error<\/h3>Always verify generated DDL by reviewing migration scripts in version control before execution.<\/p>

Use Galaxy’s SQL editor to lint and preview ALTER statements.

The AI copilot flags dangerous DDL like full-column drops, reducing production incidents.<\/p>

Related Errors and Solutions<\/h3>Error 1051 (ER_BAD_TABLE_ERROR) arises when attempting to drop a non-existent table. This differs because the table is missing rather than empty.<\/p>

Error 1091 (ER_CANT_DROP_FIELD_OR_KEY) surfaces when a DROP COLUMN references an unknown column. Ensure column names are correct.<\/p>

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