distinct sql
Distinct: helps to displays the non duplicate
records when retrieving the records from a table.
SELECT DISTINCT FIRST_NAME FROM VISITORS;distinct sql
Distinct: helps to displays the non duplicate
records when retrieving the records from a table.
SELECT DISTINCT FIRST_NAME FROM VISITORS;how to make a column unique in SQL
ALTER TABLE Persons
ADD CONSTRAINT UC_Person UNIQUE (ID,LastName);unique constraint mssql
USE AdventureWorks2012;
GO
CREATE TABLE Production.TransactionHistoryArchive4
(
TransactionID int NOT NULL,
CONSTRAINT AK_TransactionID UNIQUE(TransactionID)
);
GOsql unique
This constraint ensures all values in a column are unique.
Example 1 (MySQL): Adds a unique constraint to the id column when
creating a new users table.
CREATE TABLE users (
id int NOT NULL,
name varchar(255) NOT NULL,
UNIQUE (id)
);
Example 2 (MySQL): Alters an existing column to add a UNIQUE
constraint.
ALTER TABLE users
ADD UNIQUE (id);Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us
