MySQL error: Unknown column in 'where clause'

Question

I have a table called bank with three columns: uid, nick, balance.

I am trying to create a query that will return

Answer 1

You need to use single-quote ('), not tick marks for values of your fields

SELECT b.balance FROM bank AS b WHERE b.nick='Alex' LIMIT 1

Tick marks are used to denote field names.

Answer 2

This topic helps me a lot. The SQL was causing the error because the variables weren't with like it: select * from accounts where name='$variable' in where. But it happened when only when I add more than one condition in WHERE.

Answer 3

Another reason for such an error is, well, there is no such column in the given table. Check spelling, letter case, typographic mistakes and the actual presence of the given field in the table definition.

Answer 4

You are using the wrong "`"

Use ' instead

SELECT b.balance FROM bank AS b WHERE b.nick='Alex' LIMIT 1

Answer 5

backticks (`) are used for identifiers, like table names, column names, etc. Single quotes(') are used for string literals.

You want to do:

SELECT b.balance FROM bank AS b WHERE b.nick='Alex' LIMIT 1

Or, to be more explicit:

SELECT `b`.`balance` FROM `bank` AS b WHERE `b`.`nick`='Alex' LIMIT 1

When there is no chance of ambiguity, and when table/column names do not have special characters or spaces, then you can leave the ` off.

Here is some documentation that is dry and hard to read: http://dev.mysql.com/doc/refman/5.0/en/identifiers.html

But here is a related question on dba.stackoverflow that is easier to read: https://dba.stackexchange.com/questions/23129/benefits-of-using-backtick-in-mysql-queries

And here is a very good page that I recommend everyone read: http://www.sitepoint.com/forums/showthread.php?408497-the-big-bad-thread-of-quot-MySQL-Best-Practices-and-Other-Useful-Information-quot