<p>The column used as the document ID for an InnoDB FULLTEXT index is not the required BIGINT UNSIGNED NOT NULL type, so MySQL refuses to build the index.</p>
<p>MySQL Error 1797: ER_INNODB_FT_WRONG_DOCID_COLUMN occurs when the column chosen as the document ID for an InnoDB FULLTEXT index is not BIGINT UNSIGNED NOT NULL. Cast or alter the column to BIGINT UNSIGNED NOT NULL, then recreate the FULLTEXT index to resolve the issue.</p>
Column '%s' is of wrong type for an InnoDB FULLTEXT index
Error 1797 fires when MySQL builds an InnoDB FULLTEXT index and discovers that the referenced document ID column is not typed as BIGINT UNSIGNED NOT NULL. The engine expects that exact definition to guarantee unique, positive identifiers for the full-text index internal tables.
The error stops index creation or table import, leaving the table without the requested FULLTEXT index. Resolving it is essential for search features that rely on InnoDB FULLTEXT.
The message shows during CREATE TABLE, ALTER TABLE ADD FULLTEXT INDEX, or bulk import operations. It also appears when restoring a dump that contains an invalid DOC_ID column definition.
Without a valid FULLTEXT index, text search queries using MATCH ... AGAINST fail or execute as table scans, degrading performance. Correcting the column type restores fast, indexed text searching.
Using an INT, BIGINT SIGNED, or nullable column for the document ID violates InnoDB requirements and triggers the error. Copy-pasting table definitions from MyISAM or other engines often introduces these mismatches.
Alter the DOC_ID column to BIGINT UNSIGNED NOT NULL, or add a new compliant column and mark it AUTO_INCREMENT. Then recreate the FULLTEXT index. The steps below show both techniques.
Legacy tables migrated from MyISAM usually have an INT primary key. Changing that key to BIGINT UNSIGNED NOT NULL clears the error. Dump-and-reload workflows need a pre-migration script to update column types before import.
Always declare a BIGINT UNSIGNED NOT NULL AUTO_INCREMENT primary key on InnoDB tables meant for FULLTEXT search. Review schema-as-code repositories for correct definitions and automate checks in CI pipelines or Galaxy Collection linting.
Errors 1799 (ER_INNODB_FT_LIMIT) and 1795 (ER_INNODB_FT_WRONG_DOCID_INDEX) surface when other FULLTEXT prerequisites are unmet. They can be solved with similar schema adjustments.
Defining the DOC_ID column as BIGINT but signed or nullable breaks the requirement for positive, unique identifiers.
INT UNSIGNED lacks the 64-bit range InnoDB expects for large FULLTEXT collections and triggers the error during index creation.
Allowing NULL makes the column invalid because FULLTEXT needs a value for every row. MySQL therefore rejects the index.
A schema generated by mysqldump from an older engine may lack the proper column attributes, raising error 1797 on import.
Occurs when the index on the DOC_ID column is not defined correctly. Recreate the index as a primary or unique key.
Fires when exceeding the maximum permitted columns in a FULLTEXT index. Remove extra columns or split the index.
Appears when attempting an online schema change that InnoDB cannot perform. Switch to COPY algorithm or use pt-online-schema-change.
Not strictly, but AUTO_INCREMENT guarantees unique, positive values, so it is the safest approach.
Yes. The InnoDB FULLTEXT implementation continues to demand BIGINT UNSIGNED NOT NULL for the internal document ID.
Yes. Applications can ignore it; MySQL only needs the column for FULLTEXT indexing. Keep it internal in your data model.
Galaxy's schema-aware AI copilot warns about invalid DOC_ID definitions during code reviews and suggests compliant ALTER TABLE statements.
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