mysql check duplicate

This article refers to the link: http://blog.csdn.net/jbboy/article/details/46828917"I think the article is more suitable for learning and reference, it is worth a look"This article to provide you with three kinds of in MySQL to avoid repeated

This article to provide you with three kinds of in MySQL to avoid repeated insertion record method, mainly refers to the Ignore,replace,on DUPLICATE key update three methods, you can try to reference.Case one: Using the Ignore keywordIf the

MySQL prevent duplicate Insert Record method summaryThere are many ways to prevent MySQL from repeatedly inserting records, usually Ignore,replace,on DUPLICATE KEY UPDATE, which we can also judge in PHP.Scenario One: Using the Ignore keywordIf the

Case one: Use the Ignore keyword If the uniqueness of the record is distinguished by the primary key primary or unique index unique, it is possible to avoid duplicate insertion records: The code is as follows Copy Code 1

This article to provide you with three kinds of in MySQL to avoid repeated insertion record method, mainly refers to the Ignore,replace,on DUPLICATE key update three methods, you can try to reference.Case one: Using the Ignore keywordIf the

Insert Syntax INSERT [Low_priority | Delayed | High_priority] [IGNORE] [Into] tbl_name [(Col_name,...)] VALUES ({expr | DEFAULT},...), (...),... [on DUPLICATE KEY UPDATE col_name=expr, ...] Or: INSERT [Low_priority | Delayed | High_priority]

INSERT into on DUPLICATE key UPDATE with REPLACEinto, two commands can handle duplicate key-value problems, what difference does it make in practice?The precondition is that the table must have a unique index or primary key.1, replace found

Pt-duplicate-key-checker is also a very useful tool in Percona-toolkit to help you detect duplicate indexes or primary keys in a table. We know that indexes can be more useful than queries, but too much indexing can degrade the performance of the

Scenario One: Using the Ignore keyword If the uniqueness of the record is distinguished by the primary key primary or unique index unique, it is possible to avoid duplicate insertion records: The code is as follows: The code is as

Find duplicate data T-SQL in the database ========== first article ============ there are duplicate records under a field in a table, there are many ways, however, there is a method that is relatively efficient. The following statement: Select