PostgreSQL数据库表名的大小写实验

磨砺技术珠矶，践行数据之道，追求卓越价值
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[作者高健@博客园 luckyjackgao@gmail.com]

实验过程如下、建表：

建立带引号的表名：

postgres=# create table "GaoUser"(name varchar(10),age integer);
CREATE TABLE
postgres=# select * from GaoUser;
ERROR:  relation "gaouser" does not exist
LINE 1: select * from GaoUser;
                      ^
postgres=# select * from gaouser;
ERROR:  relation "gaouser" does not exist
LINE 1: select * from gaouser;
                      ^
postgres=# select * from "GaoUser";
 name | age 
------+-----
(0 rows)

上述的过程表明，带引号的表和不带引号的表，不是一回事。

再进一步实验：

postgres=# create table GaoUser(name varchar(10),age integer);
CREATE TABLE
postgres=# 

postgres=# create table gaouser(name varchar(10),age integer);
ERROR:  relation "gaouser" already exists
postgres=# 

postgres=# create table GAOUSER(name varchar(10),age integer);
ERROR:  relation "gaouser" already exists
postgres=#

postgres=# select * from GaoUser;
 name | age 
------+-----
(0 rows)

postgres=# select * from gaouser;
 name | age 
------+-----
(0 rows)

postgres=#

这说明，不带引号的表名，无论大写还是小写，都是一回事。

进一步的实验，可以验证此看法。

postgres=# insert into GaoUser values('user001',25);
INSERT 0 1
postgres=# insert into "GaoUser" values('user002',40);
INSERT 0 1
postgres=# select * from GaoUser;
  name   | age 
---------+-----
 user001 |  25
(1 row)

postgres=# select * from gaouser;
  name   | age 
---------+-----
 user001 |  25
(1 row)

postgres=# 

postgres=# select * from "GaoUser";
  name   | age 
---------+-----
 user002 |  40
(1 row)

postgres=# insert into GaoUser values('User003',27);
INSERT 0 1
postgres=# select * from GaoUser;
  name   | age 
---------+-----
 user001 |  25
 User003 |  27
(2 rows)

postgres=# insert into "GaoUser" values('User004',42);
INSERT 0 1
postgres=# select * from "GaoUser";
  name   | age 
---------+-----
 user002 |  40
 User004 |  42
(2 rows)

postgres=#

[作者高健@博客园 luckyjackgao@gmail.com]
回到上一级页面：PostgreSQL索引页
磨砺技术珠矶，践行数据之道，追求卓越价值