How do I create a unique two column combination in SQLite?

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CREATE UNIQUE INDEX idx_twocols ON t1t2(t1_id, t2_id). You will probably need to add NOT NULL to the declarations for each of the two columns.Unique combination of fields in SQLite? - Stack OverflowSQLite Unique Key with a combination of two columnsSqlite create unique pair of columns - Stack OverflowSQLite table constraint - unique on multiple columns - Stack OverflowДругие результаты с сайта stackoverflow.com

How do you make a unique two column combination in SQL?

To define a UNIQUE on multiple columns, we put a comma-separated columns list inside parenthesis that follows the UNIQUE keyword.

How do I create a unique column in SQLite?

Syntax. The syntax to add a unique constraint to a table in SQLite is: PRAGMA foreign_keys=off; BEGIN TRANSACTION; ALTER TABLE table_name RENAME TO old_table; CREATE TABLE table_name ( column1 datatype [ NULL | NOT NULL ], column2 datatype [ NULL | NOT NULL ], ...

Can unique key Be combination of columns?

You cannot designate the same column or combination of columns as both a primary key and a unique key or as both a primary key and a cluster key.

How do you create a unique column that alters a table?

First we write ALTER TABLE, then we list the name of the table (in our example: product ), and next we add the clause ADD CONSTRAINT with the name of the unique constraint (in our example: UQ_product_name ). This is followed by the UNIQUE keyword with column/columns (in our example it is column: name ) in parentheses.

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