sql primary key autoincrement

primary key status, this causes duplicate primary key exceptions. Therefore, if the same database has multiple instances to access, this method must be avoided. IdentityUse the primary key generation mechanism provided by the

Tags: des blog http java using OS IO fileThis article transferred from: http://289972458.iteye.com/blog/1001851Http://hi.baidu.com/zim_it/blog/item/8a2bd11205f5b56ecb80c4b7.html When using MyBatis as a persistence layer, the INSERT statement defaults to returning the number of records inserted, rather than returning the primary key value of the record, and can be configured to do so if the business layer ne

The logical design of databases is a wide range of issues. This article focuses on the primary key design issues and corresponding solutions for tables on MSSQLServer during development and application. Primary Key design status quo and problems the primary

type, an exception is thrown.Identifiers can only be guaranteed in one databaseHilo is not available when a user provides a database join for Hibernate itself, or hibernate passes JTA to obtain a database join from the application server's data source, because it does not guarantee that Hilo will access the Hi_value table in the transaction of the new database connection. In this case, the Seqhilo generator is applicable if the database system supports sequences. For a database system that supp

. MySQL does not support the sequence database (you can use identity). Specify the name of the sequenceWhen hibernate generates a primary key, it looks for sequence and assigns it to the primary key value, the primary key value is

identity). Specify the name of the sequenceWhen hibernate generates a primary key, it looks for sequence and assigns it to the primary key value, the primary key value is generated by the database, hibernate is not responsible fo

identity). Specify the name of the sequenceWhen hibernate generates a primary key, it looks for sequence and assigns it to the primary key value, the primary key value is generated by the database, hibernate is not responsible fo

When you use MyBatis to do a persistence layer, the INSERT statement defaults to not return the primary key value of the record, but instead returns the number of record bars inserted, which can be configured to perform if the business layer needs to get the primary key for the record For sequence

the company may also be duplicated, so you can not use the company's internal work number as the primary key. However, if the company name is determined, then the company's internal work number is unique, that is, by the company name Fcompanyname and the company internal work number Finternalnumber two fields together can uniquely identify a personal member, we can let Fcompanyname, Finternalnumber Two fie

Hibernate primary key Generation policy1. Automatic Growth identityFor MySQL, DB2, MS SQL Server, a database-generated primary key for generating unique identities for long, short, int typesUsing the SQL Server and MySQL self-incr

Hibernate primary key generation policy1, autogrow identity applies to MySQL, DB2, MS SQL Server, using database-generated primary keys for long, Short, the int type generates a uniquely identified self-increment field using SQL Server and MySQL, this method cannot be put in

The only database that I am still familiar with is mysql. Probably mysql users, more than 9% will use autoincrement ID as the primary key. This is understandable, because the auto-increment ID of MySQL is very efficient and convenient to use. So what do the remaining 1% users use as the primary

1. Automatic growth of identity applies to MySQL, DB2, and MSSQLServer. It uses the primary key generated by the database to generate a unique ID for long, short, and int types, and uses the auto-increment fields of SQLServer and MySQL, this method cannot be placed in Oracle... syntaxHighlighter. all (); 1. Automatic growth of identity applies to MySQL, DB2, and ms SQL