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ADD ADD CONSTRAINT ALTER ALTER COLUMN ALTER TABLE ALL AND ANY AS ASC BACKUP DATABASE BETWEEN CASE CHECK COLUMN CONSTRAINT CREATE CREATE DATABASE CREATE INDEX CREATE OR REPLACE VIEW CREATE TABLE CREATE PROCEDURE CREATE UNIQUE INDEX CREATE VIEW DATABASE DEFAULT DELETE DESC DISTINCT DROP DROP COLUMN DROP CONSTRAINT DROP DATABASE DROP DEFAULT DROP INDEX DROP TABLE DROP VIEW EXEC EXISTS FOREIGN KEY FROM FULL OUTER JOIN GROUP BY HAVING IN INDEX INNER JOIN INSERT INTO INSERT INTO SELECT IS NULL IS NOT NULL JOIN LEFT JOIN LIKE LIMIT NOT NOT NULL OR ORDER BY OUTER JOIN PRIMARY KEY PROCEDURE RIGHT JOIN ROWNUM SELECT SELECT DISTINCT SELECT INTO SELECT TOP SET TABLE TOP TRUNCATE TABLE UNION UNION ALL UNIQUE UPDATE VALUES VIEW WHERE
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SQL CREATE UNIQUE INDEX Keyword

❮ SQL Keywords Reference

CREATE UNIQUE INDEX

The CREATE UNIQUE INDEX command creates a unique index on a table (no duplicate values allowed)

Indexes are used to retrieve data from the database very fast. The users cannot see the indexes, they are just used to speed up searches/queries.

The following SQL creates an index named "uidx_pid" on the "PersonID" column in the "Persons" table:

CREATE UNIQUE INDEX uidx_pid
ON Persons (PersonID);

Note: The syntax for creating indexes varies among different databases. Therefore: Check the syntax for creating indexes in your database.

Note: Updating a table with indexes takes more time than updating a table without (because the indexes also need an update). So, only create indexes on columns that will be frequently searched against.

❮ SQL Keywords Reference