mysql duplicate row

MySQL replace into and on duplicate key update test notesMysql> CREATE TABLE tbl_insert_tmp (ID int (5), Addr_number Int (ten), name varchar, primary key (ID), unique key Udx_add R_number (Addr_number));Query OK, 0 rows affected (0.05 sec)Mysql>

How does MySQL process duplicate data? Some MySQL Data Tables may have duplicate records. In some cases, we allow the existence of duplicate data, but sometimes we also need to delete these duplicate data.This section describes how to prevent

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

Related Articles: MySQL "on duplicate key update" Syntax Insert into .. on duplicate key to update multiple rows Http://dev.mysql.com/doc/refman/5.1/zh/sql-syntax.html#insert     MySQL "on duplicate key update" Syntax If the on duplicate key update

This is often the case when developing databases:When a piece of data does not exist, insert the data. If the primary key of the data already exists in the database, update the data.How do you do this? First, query data based on the primary key, and

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

There may be duplicate records in some MySQL tables, and in some cases we allow duplicate data to exist, but sometimes we also need to delete these duplicate data.In this section we'll show you how to prevent duplicate data from appearing in a

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