mysql 查看无主键的表

-- mysql 查看无主键的表
SELECT * 
FROM information_schema.`TABLES` t 
LEFT JOIN information_schema.STATISTICS s 
    ON t.TABLE_SCHEMA = s.TABLE_SCHEMA AND t.table_name = s.TABLE_NAME AND s.INDEX_NAME = 'PRIMARY' 
WHERE t.TABLE_SCHEMA NOT IN ( 'mysql', 'performance_schema', 'information_schema', 'sys' ) 
    AND t.TABLE_TYPE = 'BASE TABLE'
    AND s.INDEX_NAME IS NULL
    and t.TABLE_SCHEMA = 'xxxxxxxxxxxxxxxxxxxx'
;