I was putting together a table in Mysql workbench and defining many-to-one relationships and which keys were foreign keys etc, and I know it put this in the actual Create script. So I\'m开发者_StackOv
I\'ve used JPA to create a database, more exactly the hibernate implementation of JPA. But anyway, at first, my question is related to JPA.
I have a situation where Project can have many Tags (and vice versa), so I have set up a has_and_belongs_to_many 开发者_如何学Gorelationship between the two.
I had posted a similar question before, but this is more specific.Please have a look at the following diagram:
I intend to create a teaming system, where each team may contain multiple contestants. The co开发者_运维问答ntestants is actually auth.User. Something similar to:
I have the following tables in a relational database: [Sensor] LocationId [PK / FK -> Location] SensorNo [PK]
I am using sql server express 2008 with mmse. i have set up a foreign key constraint between to tables and set the on delete constraint to \"set null\".
I am developing a web based application in Grails. I have come across a situation where I would like to try and suppress GORM from creating a foreign key constraint on a field in a table.
I have the following tables.... \"Floor\" (which has many) \"Area\" (which has many) \"Asset\", then I have a \"Task\" table.
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
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