列名中带有大写字母的 Postgres 查询

Question

I searched and followed various online guide however am not successful with the following query, which while doesnt give errors, it does not get the expected results.

table gBInfo:
(columns) id,userId, fromGB, fromGBId      

table User:
(columns) id, firstName, lastName

query:

select "id", "firstName", "fromGB" 
from "User" join "gBInfo"
on 'User.id' = 'gBInfo.userId';

What do I get this query to work, with uppercase letters in column and table names.

Answer 1

Single quotes are for string constants, not for identifiers. And each part of a multi-part identifier needs to be quoted separately:

select "id", "firstName", "fromGB" 
from "User" 
  join "gBInfo" on "User".id = "gBInfo"."userId";

The condition 'User.id' = 'gBInfo.userId' simply compares the string value User.id with the string value gBInfo.userId which are obviously never equal.