drop table 酮擤薛侩绢;
ERROR:  table "酮擤薛侩绢" does not exist
create table 酮擤薛侩绢 (侩绢 text, 萋拙内靛 varchar, 厚绊1A扼备 char(16));
create index 酮擤薛侩绢index1 on 酮擤薛侩绢 using btree (侩绢);
create index 酮擤薛侩绢index2 on 酮擤薛侩绢 using hash (萋拙内靛);
insert into 酮擤薛侩绢 values('哪腔磐叼胶敲饭捞', '薛A01呔');
insert into 酮擤薛侩绢 values('哪腔磐弊贰侨胶', '萋B10耖');
insert into 酮擤薛侩绢 values('哪腔磐橇肺弊贰赣', '煅Z01');
vacuum 酮擤薛侩绢;
select * from 酮擤薛侩绢;
       侩绢       | 萋拙内靛 | 厚绊1a扼备 
------------------+----------+------------
 哪腔磐叼胶敲饭捞 | 薛A01呔  | 
 哪腔磐弊贰侨胶   | 萋B10耖  | 
 哪腔磐橇肺弊贰赣 | 煅Z01  | 
(3 rows)

select * from 酮擤薛侩绢 where 萋拙内靛 = '煅Z01';
       侩绢       | 萋拙内靛 | 厚绊1a扼备 
------------------+----------+------------
 哪腔磐橇肺弊贰赣 | 煅Z01  | 
(1 row)

select * from 酮擤薛侩绢 where 萋拙内靛 ~* '煅z01';
       侩绢       | 萋拙内靛 | 厚绊1a扼备 
------------------+----------+------------
 哪腔磐橇肺弊贰赣 | 煅Z01  | 
(1 row)

select * from 酮擤薛侩绢 where 萋拙内靛 like '_Z01_';
       侩绢       | 萋拙内靛 | 厚绊1a扼备 
------------------+----------+------------
 哪腔磐橇肺弊贰赣 | 煅Z01  | 
(1 row)

select * from 酮擤薛侩绢 where 萋拙内靛 like '_Z%';
       侩绢       | 萋拙内靛 | 厚绊1a扼备 
------------------+----------+------------
 哪腔磐橇肺弊贰赣 | 煅Z01  | 
(1 row)

select * from 酮擤薛侩绢 where 侩绢 ~ '哪腔磐[叼弊]';
       侩绢       | 萋拙内靛 | 厚绊1a扼备 
------------------+----------+------------
 哪腔磐叼胶敲饭捞 | 薛A01呔  | 
 哪腔磐弊贰侨胶   | 萋B10耖  | 
(2 rows)

select * from 酮擤薛侩绢 where 侩绢 ~* '哪腔磐[叼弊]';
       侩绢       | 萋拙内靛 | 厚绊1a扼备 
------------------+----------+------------
 哪腔磐叼胶敲饭捞 | 薛A01呔  | 
 哪腔磐弊贰侨胶   | 萋B10耖  | 
(2 rows)

select *,character_length(侩绢) from 酮擤薛侩绢;
       侩绢       | 萋拙内靛 | 厚绊1a扼备 | char_length 
------------------+----------+------------+-------------
 哪腔磐叼胶敲饭捞 | 薛A01呔  |            |           8
 哪腔磐弊贰侨胶   | 萋B10耖  |            |           7
 哪腔磐橇肺弊贰赣 | 煅Z01  |            |           8
(3 rows)

select *,octet_length(侩绢) from 酮擤薛侩绢;
       侩绢       | 萋拙内靛 | 厚绊1a扼备 | octet_length 
------------------+----------+------------+--------------
 哪腔磐叼胶敲饭捞 | 薛A01呔  |            |           16
 哪腔磐弊贰侨胶   | 萋B10耖  |            |           14
 哪腔磐橇肺弊贰赣 | 煅Z01  |            |           16
(3 rows)

select *,position('叼' in 侩绢) from 酮擤薛侩绢;
       侩绢       | 萋拙内靛 | 厚绊1a扼备 | position 
------------------+----------+------------+----------
 哪腔磐叼胶敲饭捞 | 薛A01呔  |            |        4
 哪腔磐弊贰侨胶   | 萋B10耖  |            |        0
 哪腔磐橇肺弊贰赣 | 煅Z01  |            |        0
(3 rows)

select *,substring(侩绢 from 3 for 4) from 酮擤薛侩绢;
       侩绢       | 萋拙内靛 | 厚绊1a扼备 | substring 
------------------+----------+------------+-----------
 哪腔磐叼胶敲饭捞 | 薛A01呔  |            | 磐叼胶敲
 哪腔磐弊贰侨胶   | 萋B10耖  |            | 磐弊贰侨
 哪腔磐橇肺弊贰赣 | 煅Z01  |            | 磐橇肺弊
(3 rows)

