`information_schema.columns.column_comment`

mysql

type: TEXT NOT NULL

5.7-8

mariadb

type: NULL

Note:

Column comments.

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5.1-10.8

type: VARCHAR NOT NULL

Note:

Column comments.

© 2022 MariaDB

10.2-10.7

tidb

type: VARCHAR(1024) NULL

Note:

Comments contained in the column definition.

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4-6.1

postgres

cockroachdb

type: unknown

Note:

Comment on the column.

© 2022 CockroachDB

21.1-21.2

mssql