Postgresql查询会自动将大写名称转换为小写

postgresql查询自动将大写的名称转换为小写的案例，希望对大家有所帮助。一起跟随小编过来看看吧

我就废话不多说了，大家还是直接看代码吧~

SELECT sum(aa) as "recordNumber" FROM table

SELECT sum(aa) as recordNumber FROM table

postgis查询字段是将字段字段转为小写，如果需要大写的字符，需要加双引号

补充：Postgresql中表名、列名、用户名大小写问题

注意：是双引号，单引号可能会被解析成普通字符，因而是不识别的字段

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)

> 从上面可以看出，如果不加双引号，那么表名都会被转化为小写。如果想要大小写混用，需要添加双引号。

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      | {}

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