unique-constraint

相关标签：javascript jquery android 多少钱 iPhone

postgresql: error duplicate key value violates unique constraint

This question have been asked by several people but my problem seems to be different. Actually I have 开发者_开发问答to merge same structured tables from different databases in postgresql into a new D[详细]

2023-03-24 00:35 分类：问答
How to get the name of a unique constraint in postgresql?

I need to drop a unique constraint from a pos开发者_开发问答tgresql table, but I didn\'t give it a name in the schema. Does anybody know, how to get the name of such a constraint, or how to drop it?Th[详细]

2023-03-23 00:41 分类：问答
What should "length" be for this MySQL tinyblob key?

For a table I\'m creating that include IP ranges, I need to store two 128-bit (16-byte) int values in a MySQL record.Since MySQL only supports up to 8-byte ints, I\'ve found that I need to use a binar[详细]

2023-03-20 23:39 分类：问答
Database Design: need composite key + foreign key Part 2

Original Question: Database Design: need composite key + foreign key Here\'s what I need: An auto incrementing value for Id[详细]

2023-03-19 16:45 分类：问答
Enforcing unique columns

If a column is made unique in a database table structure, is there any need to do a check to see if a 开发者_开发问答new value to be inserted already exists in the table via script? Or would it be fin[详细]

2023-03-17 00:15 分类：问答
Unique Key Violation in SQL Server - Is it safe to assume Error 2627?

I need to catch violation of UNIQUE constraints in a special way by a C# application I am developing. Is it safe to assume that Error 2627 will always correspond to a violation of this kind, so that I[详细]

2023-03-15 16:44 分类：问答
Django - save() update on duplicate key

I have little application which allows a user to rate a video. The user can rate only once. So I have defined the uniqueness on the model.[详细]

2023-03-13 11:19 分类：问答
Is it possible to configure the Play Framework's CRUD module to respect @Column(unique=true) annotations?

I\'m using Play\'s CRUD module to create a simple set of admin screens.One of my models is User and I want to enforce a unique constraint on the email field.[详细]

2023-03-08 04:43 分类：问答
Hibernate: @UniqueConstraint Across Multiple Tables?

I have a data model in which a number of entities inherit some common attributes from a single superclass entity.I am using InheritanceType.JOINED on the superclass, which causes Hibernate to create a[详细]

2023-03-07 19:11 分类：问答
Extracting the configuration created by DbContext.OnModelCreating in IDatabaseInitializer

Can one access the configuration created during an implementation of DbContext.OnModelCreating in an implementation of IDatabaseInitializer.InitializeDatabase?Given an instance of DbContext, I am unab[详细]

2023-03-07 07:44 分类：问答