PostgreSQL column 'foo' does not exist

Question

I have a table that has 20 integer columns and 1 text column named \'foo\'

If I run query:

SELECT * from table_name where foo is NULL

Answer 1

If for some reason you have created a mixed-case or upper-case column name, you need to quote it, or get this error:

test=> create table moo("FOO" int);
CREATE TABLE
test=> select * from moo;
 FOO 
-----
(0 rows)
test=> select "foo" from moo;
ERROR:  column "foo" does not exist
LINE 1: select "foo" from moo;
               ^
test=> _

Note how the error message gives the case in quotes.

Answer 2

I fixed similar issues by qutating column name

SELECT * from table_name where "foo" is NULL;

In my case it was just

SELECT id, "foo" from table_name;

without quotes i'v got same error.

Answer 3

PostreSQL apparently converts column names to lower case in a sql query - I've seen issues where mixed case column names will give that error. You can fix it by putting the column name in quotation marks:

SELECT * FROM table_name where "Foo" IS NULL

Answer 4

I fixed it by changing the quotation mark (") with apostrophe (') inside Values. For instance:

insert into trucks ("id","datetime") VALUES (862,"10-09-2002 09:15:59");

Becomes this:

insert into trucks ("id","datetime") VALUES (862,'10-09-2002 09:15:59');

Assuming datetime column is VarChar.