constraints_开发者

How to provide constraint to an associative table relating to two source tables with a common foreign key?

Example scenario. In a flight schedule system, there are a pilot table which refers to a plane_type table indicating the planes the pilot is able to fly (assuming that is a many-to-one relation).[详细]

2023-04-12 18:13 分类：问答

Unable to constrain generic type

I can\'t figure out what\'s happening here. I\'m building a wrapper for a Dictionary collection. The idea is that, when the size of the collection is small, it will use a normal in-memory Dictionary;[详细]

2023-04-12 17:56 分类：问答

SQL Server Unique Constraint in a Category According To FK

The below code works great for creatin开发者_运维问答g Unique Constraints : ALTER TABLE <tablename> ADD CONSTRAINT[详细]

2023-04-12 17:07 分类：问答

Unique constraint in XML Schema

Let\'s say I have following XML开发者_如何学C file: <authors> <author>a1</author>[详细]

2023-04-12 14:36 分类：问答

In Oracle, how do I declare a unique constraint over a pair of values AND it's reverse pair

I have a table that defines th开发者_StackOverflow中文版e rule between two variants: CREATE TABLE VARIANTCOMBINATIONRULE[详细]

2023-04-12 07:07 分类：问答

MySQL express constraint as calculated column?

Columns: id INT, provice_id INT, is_province BIT Foreign key: province_id references City (id) I\'d like to express the concept: when id == province_id then is_province == 1. How can i express this?[详细]

2023-04-12 02:46 分类：问答

Two Dimensional Array Constraints: Sudoku

I am attempting to solve Sudoku as a constraint satisfaction problem for a homework assignment.I have already constructed constraints for all the elements in a particular row being distinct, as well a[详细]

2023-04-12 00:47 分类：问答

.Net generic contraint on struct types

I am trying to create a generic class whose implementation depends on the type being an Int32, Int64, double, float, or decimal.[详细]

2023-04-11 18:06 分类：问答

How to delete rows with bi-directional dependencies?

I\'m using Oracle 10g Express and trying to delete records from tables with bi-directional 开发者_JAVA百科constraints. I\'m trying to un-thread hundreds of tables and dependencies generated via Hibern[详细]

2023-04-11 13:57 分类：问答

JPA ManyToMany relation update failed due to constraint key in another relation

While developing an Eclipse GEF application using an eclipselink implementation of JPA i have found an error that has been annoying me for a while:[详细]

2023-04-10 18:05 分类：问答