![]() From your table, you set two primary keys in the same table which is wrong. You can not have two primary keys in the same table, but you can have more than two foreign keys in same table. From the options in the displayed dialog box, choose SET AS PRIMARY KEY. This primary key allows you to unique identify that row of data. It is faster than using a primary key which is not an alias of the rowid. Using SSMS, right click on the field you want to set as your Primary Key. Generate and use unique values (primary keys) for data in a given table. Notice that if you assign another integer type such as BIGINT and UNSIGNED INT to the primary key column, this column will not be an alias for the rowid column.īecause the rowid table organizes its data as a B-tree, querying and sorting data of a rowid table are very fast. If a table has the primary key that consists of one column, and that column is defined as INTEGER then this primary key column becomes an alias for the rowid column. Tables that have rowid columns are called rowid tables. The rowid column is a key that uniquely identifies the rows in the table. When you create a table without specifying the WITHOUT ROWID option, SQLite adds an implicit column called rowid that stores 64-bit signed integer. However, to make the current version of SQLite compatible with the earlier version, SQLite allows the primary key column to contain NULL values. It means that the primary key column has an implicit NOT NULL constraint. In SQL standard, the primary key column must not contain NULL values. ) Code language: SQL (Structured Query Language) ( sql )
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