Edit: There seems to be some interaction between GROUP BY/NEWID() that can cause problems if these functions are used directly in an aggregate query. Please read the posts on this thread about this, and use caution.
This script creates three functions, F_RANDOM_INTEGER, F_RANDOM_SAMPLE, and F_RANDOM_DATETIME. The last parameter of each function must be function NEWID() to generate the random number.
Theses functions are designed for applications where it is necessary to generate random integers, random datetimes, or take random samples from sets of data. Typical applications would be software testing, inventory control, auditing, and product quality testing.
Function F_RANDOM_INTEGER returns a random integer in the range of the input parameters so that the return value is >= @START_INT and <= @END_INT. It is valid for any range of two integer values.
Function F_RANDOM_SAMPLE returns a 1 or a 0 to determine if a sample should be selected, based on the input sample rate. Input parameter @SAMPLE_RATE should be between 1 and 999,999. The sample rate determines how many samples should be selected out of each 1,000,000 samples. A sample rate below 1 will never select a sample, and a sample rate above 999,999 will always select a sample. A sample rate of 1,000 = 0.1%, 50,000 = 5%, 63,775 = 6.3775%, 100,000 = 10%, and 500,000 = 50%.
F_RANDOM_DATETIME returns a random datetime value >= @START_TIME and < @END_TIME. It is valid for any datetime range. Input parameters default, if null, to @START_TIME = '19000101' and @END_TIME = '19000102’. The datetime is random to the level of clock ticks (1/300 of as second). Note that the latest time is not included in the range of datatime values that can be returned. This is to allow selection of times within adjacent time periods, without having to specify times to the level of milliseconds. This means a range of 1990-12-01 01:00:00.000 through 1990-12-01 02:00:00.000 will never return a value of 1990-12-01 02:00:00.000.
The NEWID() function is the basis of the random numbers. These functions should not to be considered random for purposes of data encryption or other high security applications. However, they should be adequate for business applications of the types mentioned above. I conducted extensive testing with the functions where I generated millions of results, analyzed the results various ways to look for non-random patterns, and I saw no evidence of non-random results.
The script also includes a demo of each function, and sample output from the demos is also included.
The demo script uses the number table function, F_TABLE_NUMBER_RANGE, available on this link:
http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=47685
if objectproperty(object_id('dbo.F_RANDOM_INTEGER'),'IsScalarFunction') = 1
begin drop function dbo.F_RANDOM_INTEGER end
go
create function dbo.F_RANDOM_INTEGER
(
@START_INTint,
@END_INTint,
@NEWIDuniqueidentifier
)
returns
int
as
/*
Function: F_RANDOM_INTEGER
This function returns a random integer
value >= @START_INT and <= @END_INT.
Valid for any integer range.
Requires newid() to be input parameter @NEWID
to generate the random number.
-- Return random integer between -100, 200000
select [Random Integer] =
[dbo].[F_RANDOM_INTEGER](-100, 200000,newid())
*/
begin
-- Set default values for input dates if they are null
if @START_INT is null begin set @START_INT = 0 end
if @END_INT is null begin set @END_INT =1000000 end
-- Set order of input parameters so that return value is always
-- the same no matter what order the input values are passed.
if @START_INT > @END_INT
select @sn = @END_INT, @en = @START_INT
else
select @sn = @START_INT, @en = @END_INT
-- Return start int if start int = end int
if @sn = @en return @sn
-- Get modulus
select @mod = @en-@sn+1
-- Get random bigint from input parameter @NEWID
select @rand_bigint = abs(convert(bigint,convert(varbinary(20),@NEWID)))
-- Get random integer
select @rand_result = @sn+(@rand_bigint%@mod)
return @rand_result
end
go
grant execute on dbo.F_RANDOM_INTEGER to public
go
if objectproperty(object_id('dbo.F_RANDOM_SAMPLE'),'IsScalarFunction') = 1
begin drop function dbo.F_RANDOM_SAMPLE end
go
create function dbo.F_RANDOM_SAMPLE
(
@SAMPLE_RATEint,
@NEWIDuniqueidentifier
)
returns
int
as
/*
Function: F_RANDOM_SAMPLE
This function returns a 1 or a 0 to determine if a sample
should be selected, based on the sample rate. It is designed
to select random samples at a specific rate.
Input parameter @SAMPLE_RATE should be between 1 and 999,999.
The sample rate determines how many samples should be
selected out of each 1,000,000 samples. A sample rate below 1
will never select a sample, and a sample rate above 999,999 will
always select a sample. 1,000 = 0.1%, 50,000 = 5%, 63,775 = 6.3775%,
100,000 = 10%, and 500,000 = 50%
Requires newid() to be input parameter @NEWID
to generate the random number.
-- Select sample 200,000 times in 1,000,000 samples (20%)
select [Random Sample] =
[dbo].[F_RANDOM_SAMPLE](200000,newid())
*/
begin
declare @rand_bigint bigint
-- Get random bigint from @NEWID
select @rand_bigint = abs(convert(bigint,convert(varbinary(20),@NEWID)))
-- Select sample if the modulus of @rand_bigint is less than the sample rate
return case when @rand_bigint%1000000 < @SAMPLE_RATE then 1 else 0 end
end
go
grant execute on dbo.F_RANDOM_SAMPLE to public
go
if objectproperty(object_id('dbo.F_RANDOM_DATETIME'),'IsScalarFunction') = 1
begin drop function dbo.F_RANDOM_DATETIME end
go
create function dbo.F_RANDOM_DATETIME
(
@START_TIMEdatetime,
@END_TIMEdatetime,
@NEWIDuniqueidentifier
)
returns
datetime
as
/*
Function: F_RANDOM_DATETIME
This function returns a random datetime
value >= @START_TIME and < @END_TIME.
Valid for any datetime range.
Input parameters default, if null, to:
@START_TIME'19000101'
@END_TIME'19000102'
Requires newid() to be input parameter @NEWID
to generate the random number.
-- Return random time between 08:30 and 12:00
select [Random Time] =
[dbo].[F_RANDOM_DATETIME]('08:30:00.000','12:00:00.000',newid())
*/
begin
declare @st datetime
declare @et datetime
declare @hours int
declare @ms int
declare @ticks bigint
declare @rand_ticks bigint
declare @rand_bigint bigint
declare @remaining_ticks int
declare @return_hours int
declare @return_ms int
-- Set default values for input dates if they are null
if @START_TIME is null begin set @START_TIME = '19000101' end
if @END_TIME is null begin set @END_TIME = '19000102' end
-- Set order of input parameters so that return value is always
-- the same no matter what order the input values are passed.
if @START_TIME > @END_TIME
select @st = @END_TIME, @et = @START_TIME
else
select @st = @START_TIME, @et = @END_TIME
-- Return start time if start time = end time
if @st = @et return @st
-- Get hours boundary difference.
-- Subtract 1 from diff, before dividing by 2 and multiplying by 2
-- so the milliseconds remaining is always positive and
-- hours is always >= zero.
set @hours = ((datediff(hh,@st,@et)-1)/2)*2
-- Get remainder milliseconds
set @ms = datediff(ms,0,@et-dateadd(hh,@hours,@st))
-- Convert remainder milliseconds to
-- SQL Server 'clock ticks' of 1/300 of a second
set @ticks = ((@ms/10)*3) + ((@ms%10)/3)
-- Add hours * tick per hour (3600*300) to give total
-- ticks between @START_TIME and @END_TIME
set @ticks = @ticks + (@hours * 0000001080000 )
-- Get random bigint from input parameter @NEWID
select @rand_bigint = abs(convert(bigint,convert(varbinary(20),@NEWID)))
-- Get random number of ticks
select @rand_ticks = @rand_bigint%@ticks
-- Get hours component of random ticks
select @return_hours = @rand_ticks/1080000
-- Get left over ticks after removing hours.
select @remaining_ticks = @rand_ticks%1080000
--Convert remaining clock ticks back to milliseconds
select @return_ms = ((@remaining_ticks/3)*10) + floor(((@remaining_ticks%3)*3.5))
-- Return the random time between the start and end time
return dateadd(ms,@return_ms,dateadd(hh,@return_hours,@st))
end
go
grant execute on dbo.F_RANDOM_DATETIME to public
go
insert into @t
select
-- Get integert in range of 1 to 10,000,000
[Random Integer] =
[dbo].[F_RANDOM_INTEGER](1,10000000,newid() )
from
-- Function F_TABLE_NUMBER_RANGE
-- available in Script Library forum
F_TABLE_NUMBER_RANGE(1,100000)
select
[Right Int] = [Random Integer]%10,
[Count] = count(*)
from
@t a
group by
[Random Integer]%10
order by
1,2
select
[Million Range] = [Random Integer]/1000000,
[Count] = count(*)
from
@t a
group by
[Random Integer]/1000000
order by
1,2
insert into @t
select
-- Sample rate = 6.3775%
[Sample Taken] = [dbo].[F_RANDOM_SAMPLE](63775,newid())
from
-- Function F_TABLE_NUMBER_RANGE
-- available in Script Library forum
F_TABLE_NUMBER_RANGE(1,100000)
select
[Sample Taken],
[Result Count] = count(*)
from
@t a
group by
[Sample Taken]
order by
1,2
go
print '-----------------------------------------------------------------'
print ' Demo F_RANDOM_DATETIME function'
print '-----------------------------------------------------------------'
print ''
select
Random_Datetime =
convert(varchar(23),[dbo].[F_RANDOM_DATETIME]( a.ST, a.ET,newid() ) ,121) ,
[Start] = convert(varchar(23),a.ST ,121) ,
[End] = convert(varchar(23),a.ET ,121) ,
a.Comment
from
(
select ST = getdate(), ET = getdate()+2 ,
Comment = 'Now thru 2 days from now' union all
select '20060101', '20060102' , 'One day diff' union all
select '20030101', '20030101' ,'Both times same' union all
select '20030101', '20030108' ,'One week diff' union all
select '20021228', '20030104' ,'One week diff' union all
select '20010701', '20010713' ,'12 day diff' union all
select '20010701', '20010714' ,'13 day diff' union all
select '20010630', '20010713' ,'13 day diff' union all
select '19901201 01:00:00.000', '19901201 02:00:00.000' ,'1 hour diff' union all
select '19901201 01:00:33.003', '19901201 02:00:33.003' ,'1 hour diff' union all
select '19901201 01:00:00.000', '19901201 01:30:00.000' ,'30 min diff' union all
select '19901201 01:00:33.447', '19901201 01:30:33.447' ,'30 min diff' union all
select '19901201 01:00:00.000', '19901201 01:05:00.000' ,'5 min diff' union all
select '19901201 01:00:29.123', '19901201 01:05:29.123' ,'5 min diff' union all
select '19901201 01:00:00.000', '19901201 01:01:00.000' ,'1 min diff' union all
select '19901201 01:00:00.000', '19901201 01:00:01.000' ,'1 sec diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.100' ,'100 ms diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.050' ,'50 ms diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.023' ,'23 ms diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.020' ,'20 ms diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.013' ,'13 ms diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.010' ,'10 ms diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.007' ,'7 ms diff' union all
select '19901201 01:00:00.000', '19901201 01:00:00.003' ,'3 ms diff' union all
select '20030101', '20030201' ,'One month diff 31 days' union all
select '20030101', '20040101' ,'One year diff' union all
select '20050101', '20070101' ,'Two year diff' union all
select '20060101', '20060301' ,'2 month diff' union all
select null, '20060101' ,'Start time null' union all
select '20060102', null ,'End time null' union all
select null, null ,'Both null' union all
select '17530101', '99991231 23:59:59.997' ,'Max datetime diff' union all
select '99991231 23:59:59.997','17530101' ,'Max datetime diff reversed'
) a
Demo Results:
-----------------------------------------------------------------
Demo F_RANDOM_INTEGER function
-----------------------------------------------------------------
-----------------------------------------------------------------
Demo F_RANDOM_SAMPLE function
-----------------------------------------------------------------
(100000 row(s) affected)
Sample Taken Result Count
------------ ------------
0 93669
1 6331
(2 row(s) affected)
-----------------------------------------------------------------
Demo F_RANDOM_DATETIME function
-----------------------------------------------------------------
Random_Datetime Start End Comment
----------------------- ----------------------- ----------------------- --------------------------
2006-07-24 08:21:22.593 2006-07-23 17:54:47.283 2006-07-25 17:54:47.283 Now thru 2 days from now
2006-01-01 06:44:36.897 2006-01-01 00:00:00.000 2006-01-02 00:00:00.000 One day diff
2003-01-01 00:00:00.000 2003-01-01 00:00:00.000 2003-01-01 00:00:00.000 Both times same
2003-01-05 01:57:02.183 2003-01-01 00:00:00.000 2003-01-08 00:00:00.000 One week diff
2003-01-01 20:02:05.550 2002-12-28 00:00:00.000 2003-01-04 00:00:00.000 One week diff
2001-07-02 11:35:11.147 2001-07-01 00:00:00.000 2001-07-13 00:00:00.000 12 day diff
2001-07-02 16:39:57.433 2001-07-01 00:00:00.000 2001-07-14 00:00:00.000 13 day diff
2001-07-06 12:33:53.087 2001-06-30 00:00:00.000 2001-07-13 00:00:00.000 13 day diff
1990-12-01 01:15:42.530 1990-12-01 01:00:00.000 1990-12-01 02:00:00.000 1 hour diff
1990-12-01 01:02:21.647 1990-12-01 01:00:33.003 1990-12-01 02:00:33.003 1 hour diff
1990-12-01 01:21:06.267 1990-12-01 01:00:00.000 1990-12-01 01:30:00.000 30 min diff
1990-12-01 01:26:17.983 1990-12-01 01:00:33.447 1990-12-01 01:30:33.447 30 min diff
1990-12-01 01:00:56.327 1990-12-01 01:00:00.000 1990-12-01 01:05:00.000 5 min diff
1990-12-01 01:03:20.423 1990-12-01 01:00:29.123 1990-12-01 01:05:29.123 5 min diff
1990-12-01 01:00:21.617 1990-12-01 01:00:00.000 1990-12-01 01:01:00.000 1 min diff
1990-12-01 01:00:00.443 1990-12-01 01:00:00.000 1990-12-01 01:00:01.000 1 sec diff
1990-12-01 01:00:00.050 1990-12-01 01:00:00.000 1990-12-01 01:00:00.100 100 ms diff
1990-12-01 01:00:00.000 1990-12-01 01:00:00.000 1990-12-01 01:00:00.050 50 ms diff
1990-12-01 01:00:00.010 1990-12-01 01:00:00.000 1990-12-01 01:00:00.023 23 ms diff
1990-12-01 01:00:00.017 1990-12-01 01:00:00.000 1990-12-01 01:00:00.020 20 ms diff
1990-12-01 01:00:00.007 1990-12-01 01:00:00.000 1990-12-01 01:00:00.013 13 ms diff
1990-12-01 01:00:00.000 1990-12-01 01:00:00.000 1990-12-01 01:00:00.010 10 ms diff
1990-12-01 01:00:00.003 1990-12-01 01:00:00.000 1990-12-01 01:00:00.007 7 ms diff
1990-12-01 01:00:00.000 1990-12-01 01:00:00.000 1990-12-01 01:00:00.003 3 ms diff
2003-01-14 09:00:09.520 2003-01-01 00:00:00.000 2003-02-01 00:00:00.000 One month diff 31 days
2003-08-27 11:47:04.100 2003-01-01 00:00:00.000 2004-01-01 00:00:00.000 One year diff
2006-11-23 03:57:21.737 2005-01-01 00:00:00.000 2007-01-01 00:00:00.000 Two year diff
2006-01-12 08:50:40.717 2006-01-01 00:00:00.000 2006-03-01 00:00:00.000 2 month diff
1933-11-15 13:39:10.050 NULL 2006-01-01 00:00:00.000 Start time null
1997-05-28 06:42:32.407 2006-01-02 00:00:00.000 NULL End time null
1900-01-01 01:50:42.743 NULL NULL Both null
2758-10-18 13:50:47.987 1753-01-01 00:00:00.000 9999-12-31 23:59:59.997 Max datetime diff
8426-03-24 13:51:08.407 9999-12-31 23:59:59.997 1753-01-01 00:00:00.000 Max datetime diff reversed
How do we convert both of them into a single SQL DateTime field such as "2015-07-16 01:23:45.000" so that it can be used in a join restricting to a date time in a different SQL File that properly has the DateTime in it?
This works well for converting the transDate Part in the select statement:
  dbo.IntegerToDate(at.transDate) as transDate
  * That returns: "2015-07-16 00:00:00.000"
* The resulting data must work directly in a Microsoft SQL Server Management Studio Query using either using the "on" statement or part of the "where" clause. In other words, NOT as a stored procedure!
Also must be able to be used as a date difference calculation when comparing the 2 files Within say + or - 5 seconds.
Hi there,I am trying to create a UID that is unique within my SQL Server. There are many users accessing the Server in seperate databases, but then I want to combine all the data from these tables, keeping the ID from each one as a primary key. I have written the following function, but when i call it as a default value for a field, it does not produce a unique number. CREATE FUNCTION GETNEXTID(@CURDATE DATETIME)RETURNS BIGINTASBEGINRETURN (SELECT CAST(CAST(DATEPART(YY,@CURDATE) AS VARCHAR) +RIGHT('0' + CAST(DATEPART(M,@CURDATE) AS VARCHAR),2) +RIGHT('0' + CAST(DATEPART(D,@CURDATE) AS VARCHAR),2) +RIGHT('0' + CAST(DATEPART(HH,@CURDATE) AS VARCHAR),2) +RIGHT('0' + CAST(DATEPART(SS,@CURDATE) AS VARCHAR),2) +RIGHT('00' + CAST(DATEPART(MS,@CURDATE) AS VARCHAR),3) AS BIGINT))END Can anyone help?
Trying to write the most effective UDF to convert INT to Datetime. We have a column from a table on AS400 that is a INT type. Some are 4, 5, 6 ,7 digits. I have the 4 digits right. I need to fix it for 5 and 6 digits.
ALTER FUNCTION IntegerToDatetime (@int INT) RETURNS DATETIME AS BEGIN DECLARE @IntegerToDatetime int DECLARE @time DATETIME SET @time = '2001-01-01' SET @IntegerToDatetime = CASE WHEN LEN(@int) = 7 THEN '20' + CAST(SUBSTRING(CAST(@int AS CHAR(7)),2,2) AS int) + '-' + CAST(SUBSTRING(CAST(@int AS CHAR(7)),4,2) AS int) + '-' + CAST(SUBSTRING(CAST(@int AS CHAR(7)),6,2) AS int) WHEN LEN(@int) = 6 THEN '19' + CAST(SUBSTRING(CAST(@int AS CHAR(6)),1,2) AS int) + '-' + CAST(SUBSTRING(CAST(@int AS CHAR(6)),3,2) AS int) + '-' + CAST(SUBSTRING(CAST(@int AS CHAR(6)),5,2) AS int) WHEN LEN(@int) = 5 THEN '200' + CAST(SUBSTRING(CAST(@int AS CHAR(5)),1,1) AS int) + '-' + CAST(SUBSTRING(CAST(@int AS CHAR(5)),2,2) AS int) + '-' + CAST(SUBSTRING(CAST(@int AS CHAR(5)),4,2) AS int) WHEN LEN(@int) = 4 THEN cast(@time AS INT)
I was just told that it is better to convert all datetime values to integers for performance reasons. Is this generally true? I am working with time series data so datetime values hold important information.
Hi All,How do you convert int value to datetime datatype in sql servere.g 900mins to hh:mm:ssRegardsOla*** Sent via Developersdex http://www.developersdex.com ***Don't just participate in USENET...get rewarded for it!
I need help with conversion type. I'm using Visual Basic 6.0 as my frontend and SQL Server 2000 as my backend. There has been existing data in the database. I would like to know how to convert an integer to datetime format. For example:
This is the actual value from the database.
1087912290 1087912327
I'd like to know how to convert it datetime format.
Hi all,I have a problem converting datetime to integer (and than back todatetime).Depending whether the time is AM or PM, same date is converted to twodifferent integer representations, which holds as true on reversalback to datetime.AM Example:declare @DI integer; declare @DD datetimeset @DI = cast(cast('3/12/2003 11:34:02 AM' as datetime) as integer)set @DD = cast (@DI as datetime)print @DI; print @DDResult:37690Mar 12 2003 12:00AMPM Example:declare @DI integer; declare @DD datetimeset @DI = cast(cast('3/12/2003 11:34:02 PM' as datetime) as integer)set @DD = cast (@DI as datetime)print @DI; print @DDResult:37691Mar 13 2003 12:00AMNow, this is not a big problem if I knew that this is how it issupposed to work. Is this how SQL Server is supposed to work?
Can someone tell me if this is a SQL Server bug? I tried this in both version 7 and 2000, the results are the same.
DECLARE @timeA DATETIME DECLARE @timeB DATETIME DECLARE @msDiff INT
SET @timeA = GETDATE() SET @msDiff = 0
WHILE @msDiff <= 10 BEGIN SET @timeB = DATEADD(ms,@msDiff,@timeA) PRINT 'If adding ' + CONVERT(VARCHAR,@msDiff) + ' milliseconds to Time B, then Time B is ' + CONVERT(VARCHAR,DATEDIFF(ms,@timeA,@timeB)) + ' millisecond greater than Time A' SET @msDiff = @msDiff + 1 END
This seems like a serious bug if an application depends heavily on milliseconds comparison.
Hi, I am writing a stored proc that will so a very simple search for users in the database. In my database I am storing a birthday as a datetime column called 'bday'. Users can search for people between a certain age range; say 23 - 30.
Here is my search query:
alter procedure sp_wm_quickSearch @lookingFor int, @mySex int, @country varchar(500), @ageTo int, @ageFrom int, @state varchar(10), @userid int
as
select * from wm_user a inner join wm_user_details b on a.userid=b.userid where a.lookingfor = 0 and a.sex = 1 and a.country = 'United States of America' and a.state = 'Washington'
I found a simple function that looks like it can do what i need it to do:
CREATE FUNCTION dbo.fnYearsApart ( @FromDate DATETIME, @ToDate DATETIME ) RETURNS INT AS BEGIN RETURN CASE WHEN @FromDate > @ToDate THEN NULL WHEN DATEPART(day, @FromDate) > DATEPART(day, @ToDate) THEN DATEDIFF(month, @FromDate, @ToDate) - 1 ELSE DATEDIFF(month, @FromDate, @ToDate) END / 12 END
MY QUESTIONS IS THIS:
How do I call this function in my query and pass it the age, and use the age as a search param. I imagine it woudl look something like this:
select * from wm_user a inner join wm_user_details b on a.userid=b.userid where a.lookingfor = 0 and a.sex = 1 and a.country = 'United States of America' and a.state = 'Washington' and fnYearsApart(a.bday, Some DateTime.Now function) < 24 and > 30
but this line doesn't work: (obviously i need to replace datetime.now
fnYearsApart(a.bday, Some DateTime.Now function) < 24 and > 30
Books online mention the existence of sample code for several custom tasks, including the one mentioned in the title. But, when I try to find this code in the location mentioned it is nowhere to be found.
I have run a search on the rest of my drive and come up empty.
Im trying to use VB.net 2005 to write a sample app to access a DB. Are there any samples for this and any samples of how I go about making the DB in the first place?
hello everone i have a table named "Concerned_Department" in which i ve a filed "Deadline"of type DateTime.i ve another table named "Cat_description" in wh i ve a filed "Max_Days"of type int in wh i ve values 1,2 and 3.in "Cat_Description" table i ve "Cat_ID" as Primary key of type int.all i want is if i select a row from "Cat_description" with "Max_Days"=1, i want to add this 1 to current date and and place it in the "deadline" field of "Concerned_Department" table.like if today is 12/02/2008 then i want to place 13/02/2008 in "Deadline" filed of "Concerned_Deprtment"tablewhen a row with "Max_Days"=1 from "Cat_Description" is selected.i am using SQL SERVER 2005 Exprees and C#(in source behind).regardsAhmed Bilal Jan
Hi,I need to extract randomly 5 records from the table "Questions". Now I useSELECT TOP 5 FROM Questions ORDERBY NEWID()And it works. The problem is that I need an additional thing: if SQLextracts record with ID=4, then it should not extract record with ID=9,because they are similar. I mean, I'd like something to tell SQL that if itextracts some questions, then it SHOULD NOT extract other ones.How can I do it?Thanks!Luke
I'm using ASP and SQL Serv 2000. What I need to get from 2 tables (company & customers) is random 10 customers from random 20 comp. Anyone got an idea how to do this??? I've spent 2 days trying to get stored proc. or T-SQL to work, but nothing good came out of it. I can get 1 comp and 10 cust, but not a grouped list of 20 comp. w/ 10 cust. each.
I was playing around with the new SQL 2005 CLR functionality andremembered this discussion that I had with Erland Sommarskog concerningperformance of scalar UDFs some time ago (See "Calling sp_oa* infunction" in this newsgroup). In that discussion, Erland made thefollowing comment about UDFs in SQL 2005:[color=blue][color=green]>>The good news is that in SQL 2005, Microsoft has addressed several of[/color][/color]these issues, and the cost of a UDF is not as severe there. In fact fora complex expression, a UDF in written a CLR language may be fasterthanthe corresponding expression using built-in T-SQL functions.<<I thought the I would put this to the test using some of the same SQLas before, but adding a simple scalar CLR UDF into the mix. The testinvolved querying a simple table with about 300,000 rows. Thescenarios are as follows:(A) Use a simple CASE function to calculate a column(B) Use a simple CASE function to calculate a column and as a criterionin the WHERE clause(C) Use a scalar UDF to calculate a column(D) Use a scalar UDF to calculate a column and as a criterion in theWHERE clause(E) Use a scalar CLR UDF to calculate a column(F) Use a scalar CLR UDF to calculate a column and as a criterion inthe WHERE clauseA sample of the results is as follows (time in milliseconds):(295310 row(s) affected)A: 1563(150003 row(s) affected)B: 906(295310 row(s) affected)C: 2703(150003 row(s) affected)D: 2533(295310 row(s) affected)E: 2060(150003 row(s) affected)F: 2190The scalar CLR UDF function was significantly faster than the classicscalar UDF, even for this very simple function. Perhaps a more complexfunction would have shown even a greater difference. Based on this, Imust conclude that Erland was right. Of course, it's still faster tostick with basic built-in functions like CASE.In another test, I decided to run some queries to compare built-inaggregates vs. a couple of simple CLR aggregates as follows:(G) Calculate averages by group using the built-in AVG aggregate(H) Calculate averages by group using a CLR aggregate that similatesthe built-in AVG aggregate(I) Calculate a "trimmed" average by group (average excluding highestand lowest values) using built-in aggregates(J) Calculate a "trimmed" average by group using a CLR aggregatespecially designed for this purposeA sample of the results is as follows (time in milliseconds):(59 row(s) affected)G: 313(59 row(s) affected)H: 890(59 row(s) affected)I: 216(59 row(s) affected)J: 846It seems that the CLR aggregates came with a significant performancepenalty over the built-in aggregates. Perhaps they would pay off if Iwere attempting a very complex type of aggregation. However, at thispoint I'm going to shy away from using these unless I can't find a wayto do the calculation with standard SQL.In a way, I'm happy that basic SQL still seems to be the fastest way toget things done. With the addition of the new CLR functionality, Isuspect that MS may be giving us developers enough rope to comfortablyhang ourselves if we're not careful.Bill E.Hollywood, FL------------------------------------------------------------------------- table TestAssignment, about 300,000 rowsCREATE TABLE [dbo].[TestAssignment]([TestAssignmentID] [int] NOT NULL,[ProductID] [int] NULL,[PercentPassed] [int] NULL,CONSTRAINT [PK_TestAssignment] PRIMARY KEY CLUSTERED([TestAssignmentID] ASC)--Scalar UDF in SQLCREATE FUNCTION [dbo].[fnIsEven](@intValue int)RETURNS bitASBEGINDeclare @bitReturnValue bitIf @intValue % 2 = 0Set @bitReturnValue=1ElseSet @bitReturnValue=0RETURN @bitReturnValueEND--Scalar CLR UDF/*using System;using System.Data;using System.Data.SqlClient;using System.Data.SqlTypes;using Microsoft.SqlServer.Server;public partial class UserDefinedFunctions{[Microsoft.SqlServer.Server.SqlFunction(IsDetermini stic=true,IsPrecise=true)]public static SqlBoolean IsEven(SqlInt32 value){if(value % 2 == 0){return true;}else{return false;}}};*/--Test #1--Scenario A - Query with calculated column--SELECT TestAssignmentID,CASE WHEN TestAssignmentID % 2=0 THEN 1 ELSE 0 END ASCalcColumnFROM TestAssignment--Scenario B - Query with calculated column as criterion--SELECT TestAssignmentID,CASE WHEN TestAssignmentID % 2=0 THEN 1 ELSE 0 END ASCalcColumnFROM TestAssignmentWHERE CASE WHEN TestAssignmentID % 2=0 THEN 1 ELSE 0 END=1--Scenario C - Query using scalar UDF--SELECT TestAssignmentID,dbo.fnIsEven(TestAssignmentID) AS CalcColumnFROM TestAssignment--Scenario D - Query using scalar UDF as crierion--SELECT TestAssignmentID,dbo.fnIsEven(TestAssignmentID) AS CalcColumnFROM TestAssignmentWHERE dbo.fnIsEven(TestAssignmentID)=1--Scenario E - Query using CLR scalar UDF--SELECT TestAssignmentID,dbo.fnIsEven_CLR(TestAssignmentID) AS CalcColumnFROM TestAssignment--Scenario F - Query using CLR scalar UDF as crierion--SELECT TestAssignmentID,dbo.fnIsEven_CLR(TestAssignmentID) AS CalcColumnFROM TestAssignmentWHERE dbo.fnIsEven(TestAssignmentID)=1--CLR Aggregate functions/*using System;using System.Data;using System.Data.SqlClient;using System.Data.SqlTypes;using Microsoft.SqlServer.Server;[Serializable][Microsoft.SqlServer.Server.SqlUserDefinedAggregate (Format.Native)]public struct Avg{public void Init(){this.numValues = 0;this.totalValue = 0;}public void Accumulate(SqlDouble Value){if (!Value.IsNull){this.numValues++;this.totalValue += Value;}}public void Merge(Avg Group){if (Group.numValues > 0){this.numValues += Group.numValues;this.totalValue += Group.totalValue;}}public SqlDouble Terminate(){if (numValues == 0){return SqlDouble.Null;}else{return (this.totalValue / this.numValues);}}// private accumulatorsprivate int numValues;private SqlDouble totalValue;}[Serializable][Microsoft.SqlServer.Server.SqlUserDefinedAggregate (Format.Native)]public struct TrimmedAvg{public void Init(){this.numValues = 0;this.totalValue = 0;this.minValue = SqlDouble.MaxValue;this.maxValue = SqlDouble.MinValue;}public void Accumulate(SqlDouble Value){if (!Value.IsNull){this.numValues++;this.totalValue += Value;if (Value < this.minValue)this.minValue = Value;if (Value > this.maxValue)this.maxValue = Value;}}public void Merge(TrimmedAvg Group){if (Group.numValues > 0){this.numValues += Group.numValues;this.totalValue += Group.totalValue;if (Group.minValue < this.minValue)this.minValue = Group.minValue;if (Group.maxValue > this.maxValue)this.maxValue = Group.maxValue;}}public SqlDouble Terminate(){if (this.numValues < 3)return SqlDouble.Null;else{this.numValues -= 2;this.totalValue -= this.minValue;this.totalValue -= this.maxValue;return (this.totalValue / this.numValues);}}// private accumulatorsprivate int numValues;private SqlDouble totalValue;private SqlDouble minValue;private SqlDouble maxValue;}*/--Test #2--Scenario G - Average Query using built-in aggregate--SELECT ProductID, Avg(Cast(PercentPassed AS float))FROM TestAssignmentGROUP BY ProductIDORDER BY ProductID--Scenario H - Average Query using CLR aggregate--SELECT ProductID, dbo.Avg_CLR(Cast(PercentPassed AS float)) AS AverageFROM TestAssignmentGROUP BY ProductIDORDER BY ProductID--Scenario I - Trimmed Average Query using built in aggregates/setoperations--SELECT A.ProductID,CaseWhen B.CountValues<3 Then NullElse Cast(A.Total-B.MaxValue-B.MinValue ASfloat)/Cast(B.CountValues-2 As float)End AS AverageFROM(SELECT ProductID, Sum(PercentPassed) AS TotalFROM TestAssignmentGROUP BY ProductID) ALEFT JOIN(SELECT ProductID,Max(PercentPassed) AS MaxValue,Min(PercentPassed) AS MinValue,Count(*) AS CountValuesFROM TestAssignmentWHERE PercentPassed Is Not NullGROUP BY ProductID) BON A.ProductID=B.ProductIDORDER BY A.ProductID--Scenario J - Trimmed Average Query using CLR aggregate--SELECT ProductID, dbo.TrimmedAvg_CLR(Cast(PercentPassed AS real)) ASAverageFROM TestAssignmentGROUP BY ProductIDORDER BY ProductID
Hi, I'm inserting a datetime values into sql server 2000 from c#
SQL server table details Table nameate_test columnname datatype No int date_t DateTime
C# coding SqlConnection connectionToDatabase = new SqlConnection("Data Source=.\SQLEXPRESS;Initial Catalog=testdb;Integrated Security=SSPI"); connectionToDatabase.Open(); DataTable dt1 = new DataTable(); dt1.Columns.Add("no",typeof(System.Int16)); dt1.Columns.Add("date_t", typeof(System.DateTime)); DataRow dr = dt1.NewRow(); dr["no"] = 1; dr["date_t"] = DateTime.Now; dt1.Rows.Add(dr); for(int i=0;i<dt1.Rows.Count;i++) { string str=dt1.Rows["no"].ToString(); DateTime dt=(DateTime)dt1.Rows["date_t"]; string insertQuery = "insert into date_test values(" + str + ",'" + dt + "')"; SqlCommand cmd = new SqlCommand(insertQuery, connectionToDatabase); cmd.ExecuteNonQuery(); MessageBox.Show("saved"); } When I run the above code, data is inserted into the table The value in the date_t column is 2007-07-09 22:10:11 000.The milliseconds value is always 000 only.I need the millisecond values also in date_t column. Is there any conversion needed for millisecond values?
Hi all, having a little problem with saving dates to sql databaseI've got the CreatedOn field in the table set to datetime type, but every time i try and run it i get an error kicked up Error "The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value.The statement has been terminated."I've tried researching it but not been able to find something similar. Heres the code: DateTime createOn = DateTime.Now;string sSQLStatement = "INSERT INTO Index (Name, Description, Creator,CreatedOn) values ('" + name + "','" + description + "','" + userName + "','" + createOn + "')"; Any help would be much appreciated
Hey :)I'm facing a lot of troubles trying to create a new pause/break-system. Right now i'm building up the query that counts how many records that is inside 2 fields. Let me first show you my table: ID (int) | stamp_start (Type: DateTime) | stamp_end (Type: DateTime) | Username (varchar)0 | 17-03-07 12:00:00 | 17-03-07 12:30:00 | Hovgaard The client will enter a start time and a end time and this query should then count how many records that are inside this periode of time. Example: The client enter starttime: 12:05 and endtime: 12:35.The query shall then return 1 record found. The same thing if the user enters 12:20 and 12:50.My current query looks like this:SELECT COUNT(ID) AS Expr1 FROM table WHERE (start_stamp <= @pausetime_start) AND (end_stamp >= @pausetime_end)But this will only count if I enter the exact same times as the one inside the table.Any ideas how I can figure this out?Thanks for your time so far :)/Jonas Hovgaard - Denmark
Hi, I have a column of type datetime in sqlserver 2000. Whenever I try to insert the date '31/08/2006 23:28:59' I get the error "...datetime data type resulted in an out-of-range datetime value" I've looked everywhere and I can't solve the problem. Please note, I first got this error from an asp.net page and in order to ensure that it wasn't some problem with culture settings I decided to run the query straight in Sql Query Anaylser. The results were the same. What else could it be? cheers, Ernest
I am inserting date and time data into a SQL Server 2012 Express table from an application. The application is providing the date and time as a string data type. Is there a TSQL way to convert the date and time string to an SQL datetime date type? I want to do the conversion, because SQL displays an error due to the
My date and time string from the application looks like : 3/11/2014 12:57:57 PM
Nothing difficult, I just need a way to generate a new datetime column based on the column [PostedDate], datetime. So basically I want to truncate the time. Thanks a lot.
select convert(datetime,'04-20-' + right(term,4)) as dt, 'Deposit' as type, a.* from dbo.status_view a
where right(term,4) always returns a string which constitutes a 4 digit year eg '1999','2004',etc.
The SQL above returns
2004-04-20 00:00:00.000 Deposit ...
Which makes me think that it is able to successfully construct the datetime object inline. But then when I try and do:
select * from ( select convert(datetime,'04-20-' + right(term,4)) as dt, 'Deposit' as type, a.* from dbo.status_view a ) where dt >= a.submit_date
I get the following error:
Syntax error converting datetime from character string.
Given that it executes the innermost SQL just fine and seems to convert the string to a datetime object, I don't see why subsequently trying to USE that datetime object for something (in this case comparison with submit_date which is a datetime in the table a) should screw it up. Help!!! Thanks...
Hi,I have a text file that contains a date column. The text file will beimported to database in SQL 2000 server. After to be imported, I wantto convert the date column to date type.For ex. the text file look likeName dateSmith 20003112Jennifer 19991506It would be converted date column to ydm database in SQL 2000 server.In the table it should look like thisName DateSmith 2000.31.12Jennifer 1999.15.06Thanks in advance- Loi -
This concerns SQL errors showing up unexpectedly and a "Sample" application.
I am running Windows XP Pro SP2 on a Dell 8600 Laptop. It is the only computer I own (or want to own) therefore, home networking not an option. A simple, stand alone computer is all I need or want, yet sometime around September or October '05 whenever I booted up, I was getting SQL error messages (e.g., missing SQLsvc file). While trying to find the problem, I was seeing indications in various places that Windows NT was my OS (what happened to Windows XP as my OS?). I'm not sure how all that happened, I certainly did not intend to make any such change.
I'm not a computer techy, nor do I have such an aspiration. However, I'm quickly discovering that in order to use a computer in any capacity, one must indeed become somewhat of a techy - like it or not!
So, I got rid of the SQL error messages from popping up at bootup and things seemed to be a bit more normal, but now (for the past 2 or 3 months), everytime I shut down, I get the pop up window that indicates a program is not ending properly and I have the option to "end now" or "cancel" to return to windows. The name in the title box of this popup is simply "Sample" -- no extension such as .exe (although I assume that's what it should be). I have no clue what this is and have searched every possible source to find the answer but to no avail. I suspect it has something to do with that blasted SQL thing that seemed to take over my computer. I searched the web for "sample.exe" and found that it may be a virus
"Virus Alert: W32.Nimda.E@mm The attachment received has been changed to: Sample.exe ... Emails itself out as Sample.exe Shared drives: Infects open network shares."
After reading the above link, I checked and, sure enough, I have this "W32nimda" file. A search as to how to eliminate it, led me to the Symantec website, which has a removal tool to download, along with 7 pages of instructions (did I mention that I did NOT want to be a computer techy?). I used Symantec antivirus 2 years ago and was glad to be rid of it, however getting completely rid of it seems to be another story and I truly wish I knew the secret to that (any hints?). I did not download this tool yet and not sure if I want to. Surely, there's an easier way! I have run my antivirus software (Trend Micro PC-Cillin), which finds nothing.
I seem to be getting away from the subject, although it all seems related, so I'll get back to the SQL question(s) which is, do I need it? If not, how can I get rid of it? Probably more information is required to answer this question such as how I use the computer, what applications, etc. Briefly, I do not create web pages and do not have a web page; no home network; do not play games or download music (afraid of that!); don't visit "taboo" websites. I do not have MS Word or any of the MS office line - Word Perfect 12 is my word processor. In November last year (at the same time all this started) my modem ceased to function, which I attributed to, unknowingly, plugging into a digital telephone jack at my office. I bought and installed another modem - which I could not get to work - took it back and bought wireless modem and router, which I installed and setup myself (with telephone assistance from router manufacturer, Linksys).
My web related usage is mainly research and email (a necessary evil, apparently). I also use the computer for photo storage and enhancement, graphics and Windows Media Player 9.
I apologize for this post being so lengthy, but I wanted to explain the problem with enough detail in the hope of getting a substantially beneficial answer (other attempts at other sites have been answered basically with "I dunno!" - and here's a surprise, I got the same "I dunno" from The Geek Squad at Best Buy!).
Thanks for taking the time to read all this - hope you can help!
