Generate a random number in the range 1 - 10 - sql

Question

Since my approach for a test query which I worked on in this question did not work out, I'm trying something else now. Is there a way to tell pg's random() function to get me only numbers between 1 and 10?

Answer 1

If by numbers between 1 and 10 you mean any float that is >= 1 and < 10, then it's easy:
select random() * 9 + 1
This can be easily tested with:
# select min(i), max(i) from (
select random() * 9 + 1 as i from generate_series(1,1000000)
) q;
min | max
-----------------+------------------
1.0000083274208 | 9.99999571684748
(1 row)
If you want integers, that are >= 1 and < 10, then it's simple:
select trunc(random() * 9 + 1)
And again, simple test:
# select min(i), max(i) from (
select trunc(random() * 9 + 1) as i from generate_series(1,1000000)
) q;
min | max
-----+-----
1 | 9
(1 row)

Answer 2

To summarize and a bit simplify, you can use:
-- 0 - 9
select floor(random() * 10);
-- 0 - 10
SELECT floor(random() * (10 + 1));
-- 1 - 10
SELECT ceil(random() * 10);
And you can test this like mentioned by #user80168
-- 0 - 9
SELECT min(i), max(i) FROM (SELECT floor(random() * 10) AS i FROM generate_series(0, 100000)) q;
-- 0 - 10
SELECT min(i), max(i) FROM (SELECT floor(random() * (10 + 1)) AS i FROM generate_series(0, 100000)) q;
-- 1 - 10
SELECT min(i), max(i) FROM (SELECT ceil(random() * 10) AS i FROM generate_series(0, 100000)) q;

Answer 3

If you are using SQL Server then correct way to get integer is
SELECT Cast(RAND()*(b-a)+a as int);
Where
'b' is the upper limit
'a' is lower limit

Answer 4

(trunc(random() * 10) % 10) + 1

Answer 5

The correct version of hythlodayr's answer.
-- ERROR: operator does not exist: double precision % integer
-- LINE 1: select (trunc(random() * 10) % 10) + 1
The output from trunc has to be converted to INTEGER. But it can be done without trunc. So it turns out to be simple.
select (random() * 9)::INTEGER + 1
Generates an INTEGER output in range [1, 10] i.e. both 1 & 10 inclusive.
For any number (floats), see user80168's answer. i.e just don't convert it to INTEGER.

Answer 6

Example
SELECT RAND()*(min-max)+max

Answer 7

Actually I don't know you want to this.
try this
INSERT INTO my_table (my_column)
SELECT
(random() * 10) + 1
;

Answer 8

This stored procedure inserts a rand number into a table. Look out, it inserts an endless numbers. Stop executing it when u get enough numbers.
create a table for the cursor:
CREATE TABLE [dbo].[SearchIndex](
[ID] [int] IDENTITY(1,1) NOT NULL,
[Cursor] [nvarchar](255) NULL)
GO
Create a table to contain your numbers:
CREATE TABLE [dbo].[ID](
[IDN] [int] IDENTITY(1,1) NOT NULL,
[ID] [int] NULL)
INSERTING THE SCRIPT :
INSERT INTO [SearchIndex]([Cursor]) SELECT N'INSERT INTO ID SELECT FLOOR(rand() * 9 + 1) SELECT COUNT (ID) FROM ID
CREATING AND EXECUTING THE PROCEDURE:
CREATE PROCEDURE [dbo].[RandNumbers] AS
BEGIN
Declare CURSE CURSOR FOR (SELECT [Cursor] FROM [dbo].[SearchIndex] WHERE [Cursor] IS NOT NULL)
DECLARE #RandNoSscript NVARCHAR (250)
OPEN CURSE
FETCH NEXT FROM CURSE
INTO #RandNoSscript
WHILE ##FETCH_STATUS IS NOT NULL
BEGIN
Print #RandNoSscript
EXEC SP_EXECUTESQL #RandNoSscript;
END
END
GO
Fill your table:
EXEC RandNumbers

Answer 9

Try This:
Select (ROW_NUMBER() OVER (ORDER BY ItemDesc ASC)+15000) as ID, ItemCode, ItemDesc

Answer 10

Using Postgres, here is how to generate random number between any 2 numbers, say, min and max:
Including min and Excluding max,
SELECT floor(random() * (max - min)) + min;
Including both min and max,
SELECT floor(random() * (max - min + 1)) + min;
So to get numbers between 1 and 10 (including 10),
min = 1, max = 10
SELECT floor(random() * (10 - 1 + 1)) + 1;
In general, you can use this formula to get random integer numbers between any min and max numbers.