Do not auto-increment composite primary key columns in bake migration#1095
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Baking a migration with multiple integer primary key columns, e.g. a join
table:
bin/cake bake migration CreateArticlesTags article_id:integer:primary tag_id:integer:primary
generated `autoIncrement => true` on every integer primary key column. MySQL
then rejects the table:
SQLSTATE[42000]: Syntax error or access violation: 1075 Incorrect table
definition; there can be only one auto column and it must be defined as a key
By convention only a single integer primary key auto-increments; a composite
primary key (typical for join tables) must not. ColumnParser now only emits
autoIncrement when there is exactly one primary key column.
ADmad
approved these changes
Jul 3, 2026
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Problem
Baking a join-table migration with a composite integer primary key, as the docs recommend:
generates
'autoIncrement' => trueon both primary key columns. MySQL then rejects the table:Reported in cakephp/cakephp#19524.
Fix
By convention only a single integer primary key auto-increments; a composite primary key (the normal shape for join tables) must not.
ColumnParser::parseFields()now only emitsautoIncrementwhen there is exactly one primary key column. Single-PK behavior is unchanged.Added
testParseFieldsCompositePrimaryKeycovering the regression.Resolves #1096