SELECT
COLUMN_COMMENT
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_SCHEMA = 'db-name' AND
TABLE_NAME = 'table-name' AND
COLUMN_NAME = 'column-name'
http://dev.mysql.com/doc/refman /5.0/en/columns-table.html
SELECT
COLUMN_COMMENT
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_SCHEMA = 'db-name' AND
TABLE_NAME = 'table-name' AND
COLUMN_NAME = 'column-name'