Hey I am using the following tables. My table course_enrollments references the user_id and the course_id. Both columns combined are set unique.
When describing relationships between entities have I understood it correct if it the occurrence of a primary key in the table, lets say A has in table B that determines whether it is a one-to-one, on
I\'m wondering what kind 开发者_JAVA技巧of PK I should be choosing for this table in MySQL. Almost all the SELECT operations will involve the DATETIME (date ranges, a specific date, etc.).
Hai, like the title.. I just wanna make sure how if I want to update primary key in 开发者_运维百科LINQ? I did google and found that it`s impossible to update Id in Linq. the other way is I delete the
I have a pretty simple table with 5 columns: key, datetime, title, body, image The user selects a title from a dropdown box and a form is populated with the datetime, body, and image. When I try to
This question already has an answer here: Closed 11 years ago. Possible Duplicate: adding primary key to sql view
Using System.Collections how to create a collection with two primary keys ? I mean new entries with the same combination are avoided but each key can be used with other keys (like combining two prima
Full disclosure...Trying feverishly here to learn more about databases so I am putting in the time and also tried to get this answer from the source to no avail.
I need to create a primary key scheme for a system that will need peer to peer replication. So I\'m planning to combine a unique system ID and a sequential number in some way to come up with unique ID
I have two tables: members ( userid int primary key ) log开发者_Go百科in_history ( userid int, login datetime
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