constraints
Entity Framework Code First contraint when one column value depends on another
I have the following model: class RentOrder { public DateTime StartDate { get; set; } public DateTime EndDate { get; set; }[详细]
2023-03-28 02:07 分类:问答SQL Table inheritance causing duplicate records in base table even though primary key constraint is set
I have a problem where lets say I have a people table that is inherited by a student table and a teacher table. if I do an INSERT INTO student and an INSERT INTO teacher and specify the primary key of[详细]
2023-03-27 13:38 分类:问答ALTER TABLE constraint problem
I\'m trying to run the following SQL statement: IF OBJECT_ID(\'MyTable\') IS NOT NULL DROP TABLE MyTable[详细]
2023-03-27 07:02 分类:问答How to guarantee uniqueness when N tables have 1:1 relationship with a common table?
Lets suppose I have a scenario with the following model: An Animal table which represents any开发者_StackOverflow中文版 animal, a Dog table and a Bird table, each one with a 1:1 relationship with the[详细]
2023-03-27 02:27 分类:问答using static methods of a constrained generic type C#
I have a generic class: public class Foo<T> where T: Interface { } the interface that T is being forced to implement has 2 static methods defined inside of it.[详细]
2023-03-26 13:14 分类:问答Can mySQL define specific columns as UNIQUE based on another column?
Suppose I have a table: CREATE TABLE `ml_vendor_refs` ( `id` int(11) NOT NULL AUTO_INCREMENT, `ml_id` int(11) NOT NULL,[详细]
2023-03-25 23:22 分类:问答Thread-Safety and the Foreign Key Constraint
Background Given: a set of threads each thread has its own data source objects in each data source references objects in other data sources[详细]
2023-03-24 23:29 分类:问答Mysterious behaviour change of NUnit constraints
The following tests pass when using NUnit 2.4.8 and fail with NUnit 2.5.10: using NUnit.Framework; namespace SimpleTests[详细]
2023-03-24 18:22 分类:问答Constraint in MS SQL
We have table Person(Id, Name, Type) and Role(Id, Name) and a binding M:N table Person_Role(Person_Id, Role_Id) which means开发者_如何学编程 \"a person can have set of roles\".[详细]
2023-03-24 02:13 分类:问答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