外键与数据库设计

Posted 2021-02-26

More for me than anything else

SHOW CREATE TABLE `tablename`
DESCRIBE `table`
EXPLAIN SELECT ...
ALTER TABLE playlist_events ADD FOREIGN KEY (playlist_id) REFERENCES playlists (id)
ALTER TABLE playlists CONVERT TO CHARACTER SET utf8
ALTER TABLE tbl_name DROP FOREIGN KEY fk_symbol
 
-- Insert data from other table
INSERT INTO TestTable (FirstName, LastName)
SELECT FirstName, LastName
FROM Contact
WHERE EmailPromotion = 2