![]() This will insert a default unique value to the Id column. When inserting the records, we simply have to specify “default” as value for the first column. This will ensure that whenever a new record is inserted in the EngStudents1 table, by default, the NEWID() function generates a unique value for the Id column. ![]() To set a default value for the column we will use the default keyword and set the default value as the value returned by the ‘NEWID()’ function. Let’s create a table EngStudents1 within the EngDB but this time we change the data type of the Id column from INT to UNIQUEIDENTIFIER. ![]() Now, let’s see how GUID can be used to solve this issue This causes the violation of primary key constraint for the Students table. You can see that students Shane and Sally both have Ids of 1 while Jonny and Edward both have Ids of 2. You can directly use this with INSERT statement to insert new row in table. This will return a new random uniqueidentifier e.g. This is when we need to use the GUID data type. If you want to generate a new Guid (uniqueidentifier) in SQL server the you can simply use the NEWID() function. However, what if we want records to have unique values across multiple databases? For instance, we want that the Id column of the EnglishStudents table and the MathStudents table to have unique values, even if they belong to different databases. To query more records radomly, increase the TOP value.SELECT * FROM MathDB. id name age gender maritalstatus 1 SAM M Single 2 BOB M Married 3 JEN F Single 4 BOB M Married The reason I want to have unique identifier is because some of the records are duplicates of each other and I want to remove the duplicates. The following example queries a random record from the Production.Product table using the NEWID() function. SELECT Query random data with the NEWID() function Have the unique identifier as your primary key by all means, but put in an identity column and make this your clustering key. I would strongly advise against this set up. Then, the variable is assigned a value by using the SET statement. The following example declares a local variable called as a variable of uniqueidentifier data type. Using uniqueidentifier and variable assignment ,('Maison Dewey', 'Catherine Dewey', 'Rue Joseph-Bens 532', 'Bruxelles', NULL, ,('Ernst Handel', 'Roland Mendel', 'Kirchgasse 6', 'Graz', NULL, ,('Cactus Comidas para Ilevar', 'Patricio Simpson', 'Cerrito 333', 'Buenos Aires', NULL, ,('Wellington Importadora', 'Paula Parente', 'Rua do Mercado, 12', 'Resende', 'SP', ('Wartian Herkku', 'Pirkko Koskitalo', 'Torikatu 38', 'Oulu', NULL, ![]() PostalCode, CountryRegion, Telephone, Fax) (Company, ContactName, Address, City, StateProvince, Creating a table using NEWID for uniqueidentifier data type. In assigning the default value of NEWID(), each new and existing row has a unique value for the CustomerID column. The following example creates the cust table with a uniqueidentifier data type, and uses NEWID to fill the table with a default value. This number is shown only for illustration. The value returned by NEWID is different for each computer.
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