postgresql查询自动将大写的名称转换为小写的案例

SELECT sum (aa) as "recordNumber" FROM table

SELECT sum (aa) as recordNumber FROM table

highgo=# create table "ExChange" (id int );

CREATE TABLE

highgo=# create table ExChange (id int );

CREATE TABLE

highgo=# \d

   List of relations

  Schema | Name | Type | Owner

----------------+----------+-------+--------

  oracle_catalog | dual | view | highgo

  public   | ExChange | table | highgo

  public   | exchange | table | highgo

  public   | myt | table | highgo

  public   | t1 | table | highgo

  public   | tran | table | highgo

(6 rows )

highgo=# insert into exchange values (1);

INSERT 0 1

highgo=# insert into "ExChange" values (2);

INSERT 0 1

highgo=# select * FROM exchange ;

  id

----

  1

(1 row)

highgo=# select * FROM ExChange ;

  id

----

  1

(1 row)

highgo=# select * FROM "ExChange" ;

  id

----

  2

(1 row)

highgo=# insert into ExChange values (2);

INSERT 0 1

highgo=# select * FROM "ExChange" ;

  id

----

  2

(1 row)

highgo=# select * FROM exchange ;

  id

----

  1

  2

(2 rows )

highgo=# create table exchange (ID int ,id int );

ERROR: 42701: column "id" specified more than once

highgo=# create table exchange (ID int , name text);

CREATE TABLE

highgo=# select id from exchange ;

  id

----

(0 rows )

highgo=# select ID from exchange ;

  id

----

(0 rows )

highgo=# select "ID" from exchange ;

ERROR: 42703: column "ID" does not exist

LINE 1: select "ID" from exchange ;

highgo=# \d exchange

  Table "public.exchange"

  Column | Type | Modifiers

--------+---------+-----------

  id | integer |

  name | text |

highgo=# \du

      List of roles

  Role name |    Attributes    | Member of

-----------+------------------------------------------------------------+-----------

  aaa |        | {}

  gpadmin | Superuser, Create role, Create DB    | {}

  highgo | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

  replica | Replication      | {}

highgo=# create table AAA;

ERROR: 42601: syntax error at or near ";"

LINE 1: create table AAA;

    ^

highgo=# create user AAA;

ERROR: 42710: role "aaa" already exists

highgo=# create user "AAA" ;

CREATE ROLE

highgo=# \du

      List of roles

  Role name |    Attributes    | Member of

-----------+------------------------------------------------------------+-----------

  AAA |        | {}

  aaa |        | {}

  gpadmin | Superuser, Create role, Create DB    | {}

  highgo | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

  replica | Replication      | {}