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How to generate a sequence in mysql

Submitted by: @import:stackexchange-dba··
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generatemysqlsequencehow

Problem

Consider this table in mysql

create table numbers (number int);
insert into numbers values (3), (2), (9);
select * from numbers;

+--------+
| number |
+--------+
|      3 |
|      2 |
|      9 |
+--------+


Is there a simple query to generate a table with the following columns

  • The numbers from 1 till 10



  • 1 if the number is present in the table numbers, and 0 otherwise



I guess you have to create a sequence of numbers in order to do this. If possible, I want to create such a sequence without storing it in the database.

Related question: is there a select query that generates a sequence of numbers from 1 till 10 (or 100 or 1000)?

Solution

IN MariaDB

MariaDB has a SEQUENCE Storage Engine. So, if you are using MariaDB, all your sequence troubles are over (or have just begun).

Sequence of 10 numbers

select * from seq_1_to_10;


NOT USING TABLES

Sequence of 10 numbers

select * from
(select 0 x union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A;


Sequence of 100 numbers

select (t*10+u+1) x from
(select 0 t union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A,
(select 0 u union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) B
order by x;


Sequence of 1000 numbers

select (h*100+t*10+u+1) x from
(select 0 h union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A,
(select 0 t union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) B,
(select 0 u union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) C
order by x;


Sequence of 10000 numbers

select (th*1000+h*100+t*10+u+1) x from
(select 0 th union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A,
(select 0 h union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) B,
(select 0 t union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) C,
(select 0 u union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) D
order by x;


USING TABLES

Sequence of 10 numbers

use test
drop table if exists seq10;
create table seq10
(x int not null auto_increment primary key);
insert into seq10 values (),(),(),(),(),(),(),(),(),();
select * from seq10;


Sequence of 100 numbers

use test
drop table if exists seq100;
create table seq100
(x int not null auto_increment primary key);
insert into seq100 values (),(),(),(),(),(),(),(),(),();
insert into seq100 values (),(),(),(),(),(),(),(),(),();
insert into seq100 values (),(),(),(),(),(),(),(),(),();
insert into seq100 values (),(),(),(),(),(),(),(),(),();
insert into seq100 values (),(),(),(),(),(),(),(),(),();
insert into seq100 select x + 50 from seq100;
select * from seq100;


Sequence of 1000 numbers

use test
drop table if exists seq1000;
create table seq1000
(x int not null auto_increment primary key);
insert into seq1000 values ();
set @p= -1;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
set @p=@p+1; insert into seq1000 select x+power(2,@p) from seq1000 where (x+power(2,@p)) <= 1000;
select * from seq1000;


Sequence of whatever numbers (Example: 3.5 million)

```
use test
drop table if exists seq;
create table seq
(x int not null auto_increment primary key);
insert into seq values ();
set @maxseq = 3500000;
set @p = -1;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select x+power(2,@p) from seq where (x+power(2,@p)) <= @maxseq;
set @p=@p+1; insert into seq select

Code Snippets

select * from seq_1_to_10;
select * from
(select 0 x union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A;
select (t*10+u+1) x from
(select 0 t union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A,
(select 0 u union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) B
order by x;
select (h*100+t*10+u+1) x from
(select 0 h union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A,
(select 0 t union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) B,
(select 0 u union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) C
order by x;
select (th*1000+h*100+t*10+u+1) x from
(select 0 th union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) A,
(select 0 h union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) B,
(select 0 t union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) C,
(select 0 u union select 1 union select 2 union select 3 union select 4 union
select 5 union select 6 union select 7 union select 8 union select 9) D
order by x;

Context

StackExchange Database Administrators Q#75785, answer score: 30

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