I am using "PostgreSQL 9.3.5"
I have a Table(StackOverflowTable) with columns (SoId,SoName,SoDob).
I want a Sequence generator for column SoId which is a Alpha-numeric value.
I want to auto increment a Alpha-Numeric Value in postgresql.
For eg : SO10001, SO10002, SO10003.....SO99999.
Edit:
If tomorrow i need to generate a Sequence which can be as SO1000E100, SO1000E101,... and which has a good performance. Then what is the best solution!
Use sequences and default value for id:
postgres=# CREATE SEQUENCE xxx;
CREATE SEQUENCE
postgres=# SELECT setval('xxx', 10000);
setval
--------
10000
(1 row)
postgres=# CREATE TABLE foo(id text PRIMARY KEY
CHECK (id ~ '^SO[0-9]+$' )
DEFAULT 'SO' || nextval('xxx'),
b integer);
CREATE TABLE
postgres=# insert into foo(b) values(10);
INSERT 0 1
postgres=# insert into foo(b) values(20);
INSERT 0 1
postgres=# SELECT * FROM foo;
id | b
---------+----
SO10001 | 10
SO10002 | 20
(2 rows)
START [ WITH ] 10000 instead of separate setval('xxx', 10000).You can define default value of your column as a concatenation of S and a normal sequence as bellow:
CREATE SEQUENCE sequence_for_alpha_numeric
INCREMENT 1
MINVALUE 1
MAXVALUE 9223372036854775807
START 1
CACHE 1;
CREATE TABLE table1
(
alpha_num_auto_increment_col character varying NOT NULL,
sample_data_col character varying,
CONSTRAINT table1_pkey PRIMARY KEY (alpha_num_auto_increment_col)
)
;
ALTER TABLE table1 ALTER COLUMN alpha_num_auto_increment_col SET DEFAULT TO_CHAR(nextval('sequence_for_alpha_numeric'::regclass),'"S"fm000000');
Test:
^
insert into table1 (sample_data_col) values ('test1');
insert into table1 (sample_data_col) values ('test2');
insert into table1 (sample_data_col) values ('test3');
select * from table1;
alpha_num_auto_increment_col | sample_data_col
------------------------------+-----------------
S000001 | test1
S000002 | test2
S000003 | test3
(3 lignes)
How to use sequences
How to use to_char function.
Create A sequence like below
CREATE SEQUENCE seq_autoid
INCREMENT 1
MINVALUE 1
MAXVALUE 9223372036854775807
START 10000
Create A Function to generate alpha numeric id
create or replace function auto_id () returns varchar as $$
select 'SO'||nextval('seq_autoid')
$$ language sql
and try this example table
create table AAA(id text ,namez text)
insert into AAA values (auto_id(),'MyName')
insert into AAA values (auto_id(),'MyName1')
insert into AAA values (auto_id(),'MyName2')
S0I would not generate that value at all. I would rather use aserialcolumn and a view that formats the generated (numeric) id in the way you want it. Requires less space and less overhead to generate the number.