Like is a common string comparison operator and should only be used when you have a fragment of the target character string and cannot use the exact search method.
USE AdventureWorks
FROM Sales.SalesOrderDetail
WHERE CarrierTrackingNumber LIKE '4911% -- To return records where CarrierTrackingNumber start with '4911'
For strings comparison where you are sure about values just use ‘=’ operator.
USE AdventureWorks
SELECT *
FROM Person.Contact
WHERE FirstName = '4911-403C-98' -- To return records where CarrierTrackingNumber is exactly '4911-403C-98'
Instead of ‘=’, ‘Like’ operator can be used for exact search but performance of ‘=’ operator for such cases will be much better as compare to ‘Like’ operator. Let’s see
Performance Difference:
USE AdventureWorks
go
SELECT *
FROM Sales.SalesOrderDetail
WHERE CarrierTrackingNumber = '4911-403C-98'
go
SELECT *
FROM Sales.SalesOrderDetail
WHERE CarrierTrackingNumber LIKE '4911-403C-98'
Boolean search commands have been used by professionals for searching through traditional databases for years. Despite this, they are overkill for the average web user. The commands described on the Search Engine Math page provide the same basic functionality as Boolean commands and are also supported by all the major search services. If you are new to searching, start off learning how to search better by first reading the Search Engine Math page, rather than trying to learn Boolean commands. I'm certain you'll find it easier. At SourcingLab you can easily create Boolean searches across multiple platforms and store them for future searches.
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