SQL和Case不敏感条件

Question

I have noticed in MySQL a where clause like WHERE x = 'Test' will match regardless of case ('TEST', 'test', etc.)

When using PDO, is it fair to assume that this is the case with most database servers? For example, If I were to use MSSQL or Oracle, would this be the same case?

Answer 1

It's not the server that it depends on, but the collation. Most databases will default to a case insensitive collation, so you can assume that, but if you ever run into one that is case sensitive it is easy to change.

Answer 2

Oracle is case sensitive with data by default eg

select * from 'test';

does not equal

select * from 'TEST';

Been a while since I last used them but I seem to recall Informix beiung case sensitive and Sybase I think is dependant on the collation.

As noted by other respondandt SQL Server is dependant on the collation.

So I think the only real answer is it depends on the RDBMS

Answer 3

SQL Server is case insensitive by default. In SQL Server you can use Collation to use case sensitive comparisons, see here .

Oracle is case sensitive by default. You can use the 'UPPER' statement to perform case insensitive searches, see here .

Answer 4

You're correct, sql in general is case insensitive for string matching and that goes for almost all servers.

Here's an article showing how to do a case sensivive match in different ways though if you need it!

http://vyaskn.tripod.com/case_sensitive_search_in_sql_server.htm