WebJan 20, 2024 · ON DUPLICATE KEY UPDATE id = LAST_INSERT_ID (id), mac = VALUES (mac), broadcast = VALUES (broadcast), ibytes = VALUES (ibytes), ipackets = VALUES (ipackets), last_change = VALUES (last_change), mask = VALUES (mask), metric = VALUES (metric), mtu = VALUES (mtu), obytes = VALUES (obytes), ierrors = VALUES … WebNov 12, 2024 · MySQL 2024/11/12 「INSERT … ON DUPLICATE KEY UPDATE 構文」を利用すると、該当レコードが存在しないときはINSERTを行い、存在する場合はUPDATEしてくれます。 ここでは、「INSERT … ON DUPLICATE KEY UPDATE 構文」の動作確認を行います。 目次 動作確認 レコードが存在しないとき レコードが存在するとき CASE …
INSERT ON DUPLICATE KEY UPDATE in MySQL - GeeksforGeeks
WebON DUPLICATE KEY UPDATE id=id (it won't trigger row update even though id is assigned to itself). If you don't care about errors (conversion errors, foreign key errors) … http://www.codebaoku.com/it-mysql/it-mysql-280833.html chip richmond va
mysql - On duplicate key update throws an en duplicate entry …
WebMay 29, 2006 · ON DUPLICATE KEY UPDATE works. As I recall: Lock 1) Transaction 1 locks row for INSERT Lock 2) Transaction 2 tries to locks row for UPDATE (goes into queue) Lock 3) Transaction 1 tries to locks row for UPDATE (goes into queue) It is reasonable not to release Lock 1, but why MySQL tries to create Lock 3? WebApr 10, 2024 · 在MySQL中,InnoDB引擎类型的表支持了外键约束。外键的使用条件:1.两个表必须是InnoDB表,MyISAM表暂时不支持外键(据说以后的版本有可能支持,但至少目前不支持);2.外键列必须建立了索引,MySQL 4.1.2以后的版本在建立外键时会自动创建索引,但如果在较早的版本则需要显示建立;3.外键关系的 ... WebTo make it easier to reload dump files for tables with foreign key relationships, mysqldump automatically includes a statement in the dump output that disables foreign_key_checks. This enables you to import the tables in any order in case the dump file contains tables that are not correctly ordered for foreign keys. grapevine bars with live music