how to create unique id in mysql table

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

Use LAST_INSERT_ID of MySQL to determine the unique ID value of each table Shard in the MySQL data table structure. generally, a 'id' field with the 'auto _ INCREMENT 'extension property is defined, to ensure that each record of the data table can

MySQL table sharding Methods: MySQL I. Let me explain why Table sharding is required. When a piece of data reaches several millions, it takes more time for you to query the data at a time. If there is a joint query, I think it may die there. The

This article mainly describes how to generate globally unique IDs in a distributed system. Preface Simply generating global IDs is not a challenge, generating a global unique ID to meet the following requirements: Ensure that the generated ID is

The table structure is the same except for the index of the table name, and if the ' id ' field of each table is still in the ' auto_increment ' way, the ID cannot only determine a single record. This requires a mechanism in addition to the various

In addition to the index of different table names, the table structure is the same. If the 'id' field of each table still adopts the 'Auto _ INCREMENT 'method, ID cannot identify only one record. In this case, an External table shard mechanism is

Http://www.cnblogs.com/lsx1993/p/4663125.html "Database primary key scheme in distributed environment" [Http://www.2cto.com/database/201309/243195.html] Using a self-added primary key ID is certainly the best fit when using only a single database.

In addition to the index of different table names, the table structure is the same. If the 'id' field of each table still adopts the 'Auto _ INCREMENT 'method, ID cannot identify only one record.In this case, an External table shard mechanism is

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

This article will introduce the differences between unique and primary constraints in mysql. unique and primary are the types we often use when creating mysql. Next I will introduce them to you. Fields defining the UNIQUE constraint cannot contain