PostgreSQL: ERROR: Column Does Not Exist
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Join For FreeI’ve been playing around with PostgreSQL recently and in particular the Northwind dataset typically used as an introductory data set for relational databases.
Having imported the data I wanted to take a quick look at the employees table:
postgres=# SELECT * FROM employees LIMIT 1;
EmployeeID | LastName | FirstName | Title | TitleOfCourtesy | BirthDate | HireDate | Address | City | Region | PostalCode | Country | HomePhone | Extension | Photo | Notes | ReportsTo | PhotoPath
------------+----------+-----------+----------------------+-----------------+------------+------------+-----------------------------+---------+--------+------------+---------+----------------+-----------+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------+--------------------------------------
1 | Davolio | Nancy | Sales Representative | Ms. | 1948-12-08 | 1992-05-01 | 507 - 20th Ave. E.\nApt. 2A | Seattle | WA | 98122 | USA | (206) 555-9857 | 5467 | \x | Education includes a BA IN psychology FROM Colorado State University IN 1970. She also completed "The Art of the Cold Call." Nancy IS a member OF Toastmasters International. | 2 | http://accweb/emmployees/davolio.bmp
(1 ROW)
That works fine but what if I only want to return the ‘EmployeeID’ field?
postgres=# SELECT EmployeeID FROM employees LIMIT 1; ERROR: COLUMN "employeeid" does NOT exist LINE 1: SELECT EmployeeID FROM employees LIMIT 1;
I hadn’t realised (or had forgotten) that field names get lower cased so we need to quote the name if it’s been stored in mixed case:
postgres=# SELECT "EmployeeID" FROM employees LIMIT 1;
EmployeeID
------------
1
(1 ROW)
From my reading the suggestion seems to be to have your field names lower cased to avoid this problem but since it’s just a dummy data set I guess I’ll just put up with the quoting overhead for now.
Published at DZone with permission of Mark Needham. See the original article here.
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