标签:tor tail dual key tutorial sts tutorials man ica
数据唯一性
先建立primary index或者unique index:
INSERT IGNORE
REPLACE
https://www.tutorialspoint.com/mysql/mysql-handling-duplicates.htm
https://www.mysqltutorial.org/mysql-insert-ignore/
https://www.runoob.com/mysql/mysql-handling-duplicates.html
INSERT INTO table (a,b,c) VALUES (1,2,3) ON DUPLICATE KEY UPDAT cut = cut +1
INSERT INTO books (name) SELECT ‘MySQL Manual‘ FROM dual WHERE NOT EXISTS (SELECT id FROM books WHERE id = 1)
https://blog.csdn.net/java_2017_csdn/article/details/78517789
标签:tor tail dual key tutorial sts tutorials man ica
原文地址:https://www.cnblogs.com/zhouj-happy/p/12744450.html