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SQL Query related

 
Greenhorn
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Hi,

i'm beginner in SQL queries, When i trying to get particular records count from customer table(database), i used these queries(see below). Since, both has return the same results (display record count). What is difference between them? Which statement could be better?

select count (*) from customer_table where upper( DocumentNo ) like upper( '%12345%' )
(or)
select count(*) from customer_table where DocumentNo = '12345'
 
Rancher
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It's not a question of which statement is better - they do different things. "upper" and "like" are standard SQL features that I'm certain are explained in any SQL manual.
 
author & internet detective
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contains unnecessary code. 12345 are numbers, not uppercase characters

Which means the first query should be:


Whether this revised query or the = query is better depends on your dataset. If you know 12345 is the actual value, = is better than like because it is more specific.
 
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