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If you're asking if a table can have multiple columns as a primary key, then for MS SQL Server, the answer is yes, and it's called a composite (corrected) key.
The PRIMARY KEY constraint uniquely identifies each record in a table. Primary keys must contain UNIQUE values, and cannot contain NULL values. A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).
18 Αυγ 2019 · A composite primary key is a primary key consisting of multiple columns. Microsoft usually refers to these as multicolumn primary keys in its documentation. This article provides an example of creating a composite primary key using Transact-SQL in SQL Server.
A primary key is a column or a group of columns that uniquely identifies each row in a table. You create a primary key for a table by using the PRIMARY KEY constraint. If the primary key consists of only one column, you can define use PRIMARY KEY constraint as a column constraint: pk_column data_type PRIMARY KEY, ...
18 Απρ 2024 · In Table Designer, select the row selector for the database column you want to define as the primary key. If you want to select multiple columns, hold down the CTRL key while you select the row selectors for the other columns. Right-click the row selector for the column and select Set Primary Key.
2) SQL Server PRIMARY KEY – multiple column (composite key) example We can recreate the employee table again with the following query using the employee first and last name columns together as the primary key instead of employee id.
21 Απρ 2016 · Get multiple columns from a select subquery - Database Administrators Stack Exchange. Ask Question. Asked 12 years, 7 months ago. Modified 1 year, 9 months ago. Viewed 228k times. 54. SELECT . *, . p.name AS name, . p.image, . p.price, ( . SELECT ps.price . FROM product_special ps . WHERE p.id = ps.id. AND ps.date < NOW() .
