mysql unique row

Key differs from primary keyKey is usually the index synonym. If the keyword attribute primary key is given in the column definition, then primary key can also be specified as key only. The purpose of this is to be compatible with other database

MySQL tutorial How to use the unique index Grammar:UNIQUE KEY ' test ' (' Xref_key ', ' xref_dbname ')UNIQUE KEY ' Xref_key ' (' Xref_key ', ' xref_dbname ') The above syntax checks whether the combination of Xref_key and Xref_dbname is a unique

Concept:A primary key (primary key) uniquely identifies a property or group of properties for a row in a table. A table can have only one primary key, but there may be multiple candidate indexes. Primary keys often form referential integrity

MysqlInnoDB row lock implementation method bitsCN.com Mysql InnoDB row lock implementation method InnoDB row lock is implemented by locking the index items on the index. this is different from Oracle in MySQL, the latter is implemented by locking

This article describes how to insert duplicate values in the unique column in mysql. it is mainly based on the mysql platform. through these solutions, you can implement some new functions and applications. This article will be shared here with

Henan College of Traditional Chinese Medicine Course Design Report of MySQL Database Management  Title: Research and Implementation of MySQL Clusters       Completion date:2012January 1, December 31   Contents 1. Course Design overview 3 2. research

Mysql InnoDB row lock implementation method InnoDB row lock is implemented by locking the index items on the index. This is different from Oracle in MySQL, the latter is implemented by locking the corresponding data rows in the data block. The

What are the differences among KEY, primary key, unique key, and INDEX in MySQL? mysqlunique You can split the questions raised in the questions to solve them step by step. In MySQL, KEY and INDEX are synonymous. This problem can be simplified to

MySQL performance tuning and Architecture Design-Chapter 1 Performance Design-MySQL Replication and replication Optimization Chapter 1 scalability design-MySQL Replication Preface: MySQL Replication is a unique feature of MySQL. It can completely

MySQL常用指令，java，php程序员，数据库工程师必备。程序员小冰常用资料整理MySQL common commands (for reference)The most common display commands are:1. Display the list of databases.show databases;2. Display the data table in the library:Use MySQL;Show tables;3, display the