ERROR: column of relation does not exist PostgreSQL ,Unable to run insert query

Question

Hi I am trying to insert into a table tester3 it fails when i use the syntax

insert into tester3 (UN0, UN1) values ( 1, 'jishnu1');

but

insert into tester3 values ( 1, 'jishnu1');

is working fine.

mydb=# CREATE TABLE tester3
mydb-#    (
mydb(#     "UN0" integer,
mydb(#     "UN1" VARCHAR(40)
mydb(#    );
CREATE TABLE
mydb=# insert into tester3 (UN0, UN1) values ( 1, 'jishnu1');
ERROR:  column "un0" of relation "tester3" does not exist
mydb=# \d tester3
           Table "public.tester3"
 Column |         Type          | Modifiers
--------+-----------------------+-----------
 UN0    | integer               |
 UN1    | character varying(40) |

I think i am missing something very trivial, I tried someother column names some of them works fine and some are not working. I am confused. Does PostgreSQL have restriction in column names for which works the 1st syntax of insert query works?

---

Edit :

Checkout Girdon Linoff answer , as Frank Heikens pointed out the other column names which were working without quotes were in lower case.

Lower case column is the standard within PostgreSQL and also works without quotes

Answer 1

try this using double quotes to your column names

insert into tester3 ("UN0", "UN1") values ( 1, 'jishnu1');

Answer 2

i have my story with my database for Qgis + POSTGRES DATA i try update my table with code by Navicate UPDATE "MangLuoi"."A_Lam_D310" SET "MangLuoi"."A_Lam_D310"."Nguon"='Lâm' and ERRO : SQL]UPDATE "MangLuoi"."A_Lam_D310" SET "MangLuoi"."A_Lam_D310"."Nguon"='Lâm'

[Err] ERROR: column "MangLuoi" of relation "A_Lam_D310" does not exist LINE 1: UPDATE "MangLuoi"."A_Lam_D310" SET "MangLuoi"."A_Lam_D310"."...

Now i try UPDATE "MangLuoi"."A_Lam_D310" SET "Nguon"='Lâm'

IT show ok :)) by Message: Time: 0.035s

Affected rows: 29

Thank for share and answer.