relational-database
SQL semantics for "FOR UPDATE" & "JOIN"
I\'d like to understand the exact semantics of using \"FOR UPDATE\" in connection with \"JOIN\". Does it just lock all the rows that were effectively used to build the end result? Does it do something[详细]
2023-03-26 19:41 分类:问答Friendfeed showing same relationship twice
I was building a feed system ala facebook just for the fun and training of it but I came up with an interesting problem. Imagine this scenario:[详细]
2023-03-26 18:14 分类:问答Best practices for migrating database content from one very poor structure to one very logical?
TL;DR what\'s the best way to migrate lots of data between one very poorly structured database (with much repetition of columns, no interrelations, and duplicate data), to another highly organised and[详细]
2023-03-26 17:21 分类:问答How to decide when use ADO.NET and when to connect to the database?
I\'m learning some ADO.NET. I noticed quite a few Database functionality can also be found in ADO.NET.[详细]
2023-03-26 12:09 分类:问答SQL Conditional relationships
I\'ve come up with two approaches to the same idea and would like to avoid any obvious pitfalls by using one over the other.I have a table (tbl_post) where a single row can have many relationships to[详细]
2023-03-26 08:54 分类:问答Persisting immutable objects to a relational database
I\'ve seen certain object-oriented experts advise that domain objects (POCOs) should be immutable. That is, their state should be entirely determined at construction, and changes to state should requ[详细]
2023-03-26 05:53 分类:问答Using IDs from multiple tables in a single column
The system rules: Departments can have 0 to many divisions. A division must belong to only one department.[详细]
2023-03-26 03:29 分类:问答How can I derive the winners of a match from a table of games that relate to a table of matches?
In a database that stores tournaments I have this relational structure to store matches and their games:[详细]
2023-03-26 00:57 分类:问答Creating a simple user/group model with permissions with Hibernate (annotations)
This is most likely a very basic question, but nevertheless: Basically the User ent开发者_如何学JAVAity has an Id and a privilege enum.[详细]
2023-03-25 22:30 分类:问答How do I set up these ActiveRecord relationships properly?
I ha开发者_StackOverflow中文版ve a problem understanding how to set up the ActiveRecord relationships correctly for the following scenarios...[详细]
2023-03-25 22:01 分类:问答