Records in one table have one or more related records in a second table, but each record in the second table is related to only one record in the first table.
An association between two tables in which: · The primary key value of each record in the primary table corresponds to the value in the matching field or fields of many records in the related table. · The primary key value of each record in the related table corresponds to the value in the matching field or fields of one and only one record in the primary table. .
One-to-One Relationship Primary key
A relationship between two tables in which a single row in the first table can be related to one or more rows in the second table, but a row in the second table can be related to only one row in the first table. A typical one-to-many relationship is between the publishers table and the titles table in the pubs sample database, in which each publisher can be related to several titles, but each title can be related to only one publisher.
Type of relationship between two tables specified by the Relationships command.
A relationship where there is one uniquely identified row in one table relating to one or more rows in another table. The relationship is based on the unique key found in the first table. For example, for each video title (identified by a row with a unique key) in a Video Product table, there may be many entries (rows) in the Sales Details table for each time a customer has rented the video.
A single instance in entity A may relate to zero, one or many instances in entity B, but not vice versa. Notation is 1:M.
