composite-primary-key

问题 I have an entity OrderItem that has OrderId and ProductId integer fields and these two fields form the identity key/primary key for this table. I would like to use OData/Web API to expose such entities through a service and to be able to select OrderItem instances by they composite ID . What should be the format of the URL ? Are there any best practices for handling such scenarios? 回答1: Composite keys in the URL use syntax like this: ~/OrderItems(OrderId=1234,ProductId=1234) The "grammar" is

问题 I have a table with a composite key, and I want to do my SELECT query with that key, is there a way to put a name to the composite key or to do the query without having to add an AND let's say: SELECT * FROM MyTable WHERE PRIMARY KEY = 12345 being that primary key a composite key 回答1: No, there is no concept of SELECT * FROM MyTable WHERE PRIMARY KEY = 'PrimaryKeyName'. In other words, the predicate (WHERE clause) does not allow for this. You will need to list all columns that are contained

问题 I don't use 'id' column in DB. Instead, I use a composite primary key user_id + tmdb_id . If I add new record like this: $movie = new Movie(); $movie->user_id = 1; $movie->tmdb_id = 2; $movie->ratio = 3; $movie->save(); it works fine! But if I try to edit an existing record like this: $movie = Movie::where([ 'user_id' => 1, 'tmdb_id' => 2, ])->first(); $movie->ratio = 4; $movie->save(); Then I have the error: Unknown column 'id' in 'where clause'. The migration file looks like this: public

问题 I am currently working on a database, where a log is required to track a bunch of different changes of data. Stuff like price changes, project status changes, etc. To accomplish this I've made different 'log' tables that will be storing the data needing to be kept. To give a solid example, in order to track the changing prices for parts which need to be ordered, I've created a Table called Part_Price_Log . The primary key is composite made up of the date in which the part price is being

问题 I am currently working on a database, where a log is required to track a bunch of different changes of data. Stuff like price changes, project status changes, etc. To accomplish this I've made different 'log' tables that will be storing the data needing to be kept. To give a solid example, in order to track the changing prices for parts which need to be ordered, I've created a Table called Part_Price_Log . The primary key is composite made up of the date in which the part price is being

问题 I am currently working on a database, where a log is required to track a bunch of different changes of data. Stuff like price changes, project status changes, etc. To accomplish this I've made different 'log' tables that will be storing the data needing to be kept. To give a solid example, in order to track the changing prices for parts which need to be ordered, I've created a Table called Part_Price_Log . The primary key is composite made up of the date in which the part price is being

问题 I have two(of many) tables in a music database: Concerts: ArtistID,ConcertID,ConcetName,VenueID ConcertDetails: ConcertDate, ConcertID, Cost The ConcertDetails tables as you see, uses ConcertID which is also in the Concerts table. I combine ConcertDate & ConcertID to make a Composite Primary Key for ConcertDetails. However since this relates to ConcertID from Concerts table it also needs to be a Foreign Key. Is this ok to do? 回答1: Yes, of course. It's common for a subset of a primary key to

问题 I have two(of many) tables in a music database: Concerts: ArtistID,ConcertID,ConcetName,VenueID ConcertDetails: ConcertDate, ConcertID, Cost The ConcertDetails tables as you see, uses ConcertID which is also in the Concerts table. I combine ConcertDate & ConcertID to make a Composite Primary Key for ConcertDetails. However since this relates to ConcertID from Concerts table it also needs to be a Foreign Key. Is this ok to do? 回答1: Yes, of course. It's common for a subset of a primary key to

问题 I am new to MS Access. Could anybody tell me how to define a composite primary key in MS Access 2007. 回答1: If memory serves correctly, you can hold SHIFT while selecting the fields in the design view. Once you've selected all of the fields that are to be part of the key, press the primary key button. 回答2: Already answered, but I wanted to chime in with additional info. After solving my related problem, holding "ctrl" + clicking multiple columns in design view and then clicking the "primary

问题 I am new to MS Access. Could anybody tell me how to define a composite primary key in MS Access 2007. 回答1: If memory serves correctly, you can hold SHIFT while selecting the fields in the design view. Once you've selected all of the fields that are to be part of the key, press the primary key button. 回答2: Already answered, but I wanted to chime in with additional info. After solving my related problem, holding "ctrl" + clicking multiple columns in design view and then clicking the "primary