I am attempting to hash a string to a 64-bit value (bigint) in MySQL. I am aware of the MD5() function, which returns a 128-bit hash as a binary string. I'd be happy to just take the bottom or top 64 bits of this result. However, I cannot figure out how to get from a binary string type to a numeric type of any sort. Any pointers?
Use the CONV() function to convert the MD5 hash from base 16 to base 10 and CAST to convert it to a number:
select cast(conv(substring(md5(id), 1, 16), 16, 10) as unsigned integer) from SomeTable;
CREATE FUNCTION dbo.HexStrToVarBinary(#hexstr varchar(8000))
RETURNS varbinary(8000)
AS
BEGIN
DECLARE #hex char(1), #i int, #place bigint, #a bigint
SET #i = LEN(#hexstr)
set #place = convert(bigint,1)
SET #a = convert(bigint, 0)
WHILE (#i > 0 AND (substring(#hexstr, #i, 1) like '[0-9A-Fa-f]'))
BEGIN
SET #hex = SUBSTRING(#hexstr, #i, 1)
SET #a = #a +
convert(bigint, CASE WHEN #hex LIKE '[0-9]'
THEN CAST(#hex as int)
ELSE CAST(ASCII(UPPER(#hex))-55 as int) end * #place)
set #place = #place * convert(bigint,16)
SET #i = #i - 1
END
RETURN convert(varbinary(8000),#a)
END
GO
Source
You could also use CRC32 function that returns 32-bit unsigned value.
SELECT CRC32(id) from SomeTable;
Documentation
Related
How do I convert an id INT column in MySQL to a base 62 alphanumeric string?
Basically I really need a MySQL implementation of the following:
http://kvz.io/blog/2009/06/10/create-short-ids-with-php-like-youtube-or-tinyurl/
I needed to do this for larger-than-INT binary data (base-256 UUIDs specifically), so I created this stored function:
DELIMITER //
CREATE FUNCTION base62(x VARBINARY(16)) RETURNS VARCHAR(22) DETERMINISTIC
BEGIN
DECLARE digits CHAR(62) DEFAULT "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
DECLARE n NUMERIC(39) DEFAULT 0;
DECLARE s VARCHAR(22) DEFAULT "";
DECLARE i INT DEFAULT 1;
WHILE i <= LENGTH(x) DO
SET n = n * 256 + ORD(SUBSTR(x, i, 1));
SET i = i + 1;
END WHILE;
WHILE n > 0 DO
SET s = CONCAT(SUBSTR(digits, (n MOD 62) + 1, 1), s);
SET n = FLOOR(n / 62);
END WHILE;
RETURN s;
END//
You can remove the first loop if you've already got a numeric type. You may also wish to adjust the alphabet; for instance, the base-64 puts letters before numbers.
It is better to generate id using uuid or use auto increment to store in mysql but encode decode it while using it for front end. You can use this library to generate non sequential unique id's from numbers.
http://hashids.org
I've been using this MySQL function successfully. It takes a BIGINT parameter as input and returns BASE62 Youtube style ID's.
CREATE FUNCTION `i2s`(
`_n` BIGINT
)
RETURNS tinytext CHARSET latin1 COLLATE latin1_general_cs
LANGUAGE SQL
NOT DETERMINISTIC
NO SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
declare d char(62) default '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
declare s tinytext default '0';
declare i int default 1;
if _n>0 then set s=''; end if;
while _n > 0 do
set s = concat(substr(d, (_n mod 62) + 1, 1),s);
set _n = floor(_n / 62);
end while;
return s;
END
I have developed a function for split string in tsql but mysql don't have some built in functions. I needed to function in MYSQL as i am new in mysql. Function should accept 2 parameters
1. String to be split
2. separator (',' or whatever)
Kindly reply me.
i had found solution on the internet you can into that.
DELIMITER //
DROP FUNCTION IF EXISTS `splitAndTranslate` //
CREATE FUNCTION splitAndTranslate(str TEXT, delim VARCHAR(124))
RETURNS TEXT
DETERMINISTIC
BEGIN
DECLARE i INT DEFAULT 0; -- total number of delimiters
DECLARE ctr INT DEFAULT 0; -- counter for the loop
DECLARE str_len INT; -- string length,self explanatory
DECLARE out_str text DEFAULT ''; -- return string holder
DECLARE temp_str text DEFAULT ''; -- temporary string holder
DECLARE temp_val VARCHAR(255) DEFAULT ''; -- temporary string holder for query
-- get length
SET str_len=LENGTH(str);
SET i = (LENGTH(str)-LENGTH(REPLACE(str, delim, '')))/LENGTH(delim) + 1;
-- get total number delimeters and add 1
-- add 1 since total separated values are 1 more than the number of delimiters
-- start of while loop
WHILE(ctr<i) DO
-- add 1 to the counter, which will also be used to get the value of the string
SET ctr=ctr+1;
-- get value separated by delimiter using ctr as the index
SET temp_str = REPLACE(SUBSTRING(SUBSTRING_INDEX(str, delim, ctr), LENGTH(SUBSTRING_INDEX(str, delim,ctr - 1)) + 1), delim, '');
-- query real value and insert into temporary value holder, temp_str contains the exploded ID
SELECT <real_value_column> INTO temp_val FROM <my_table> WHERE <table_id>=temp_str;
-- concat real value into output string separated by delimiter
SET out_str=CONCAT(out_str, temp_val, ',');
END WHILE;
-- end of while loop
-- trim delimiter from end of string
SET out_str=TRIM(TRAILING delim FROM out_str);
RETURN(out_str); -- return
END//
reference http://www.slickdev.com/2008/09/15/mysql-query-real-values-from-delimiter-separated-string-ids/
In mysql they they dont support some functionality like sqlserver. so spliting will be difficult in mysql
SELECT e.`studentId`, SPLIT(",", c.`courseNames`)[e.`courseId`]
FROM ..
SELECT TRIM(SUBSTRING_INDEX(yourcolumn,',',1)), TRIM(SUBSTRING_INDEX(yourcolumn,',',-1)) FROM yourtable
CREATE FUNCTION [dbo].[SplitString]
(
#RowData nvarchar(2000),
#SplitOn nvarchar(5)
)
RETURNS #RtnValue table
(
--Id int identity(1,1),
Data nvarchar(100)
)
AS
BEGIN
Declare #Cnt int
Set #Cnt = 1
While (Charindex(#SplitOn,#RowData)>0)
Begin
Insert Into #RtnValue (data)
Select
Data = ltrim(rtrim(Substring(#RowData,1,Charindex(#SplitOn,#RowData)-1)))
Set #RowData = Substring(#RowData,Charindex(#SplitOn,#RowData)+1,len(#RowData))
Set #Cnt = #Cnt + 1
End
Insert Into #RtnValue (data)
Select Data = ltrim(rtrim(#RowData))
Return
END
I have quite a large nvarchar which I wish to pass to the HashBytes function.
I get the error:
"String or binary would be truncated.
Cannot insert the value NULL into
column 'colname', tbale 'table';
column does not allow nulls. UPDATE
fails. The statement has been
terminated."
Being ever resourceful, I discovered this was due to the HashBytes function having a maximum limit of 8000 bytes. Further searching showed me a 'solution' where my large varchar would be divided and hashed seperately and then later combined with this user defined function:
function [dbo].[udfLargeHashTable] (#algorithm nvarchar(4), #InputDataString varchar(MAX))
RETURNS varbinary(MAX)
AS
BEGIN
DECLARE
#Index int,
#InputDataLength int,
#ReturnSum varbinary(max),
#InputData varbinary(max)
SET #ReturnSum = 0
SET #Index = 1
SET #InputData = convert(binary,#InputDataString)
SET #InputDataLength = DATALENGTH(#InputData)
WHILE #Index <= #InputDataLength
BEGIN
SET #ReturnSum = #ReturnSum + HASHBYTES(#algorithm, SUBSTRING(#InputData, #Index, 8000))
SET #Index = #Index + 8000
END
RETURN #ReturnSum
END
which I call with:
set #ReportDefinitionHash=convert(int,dbo.[udfLargeHashTable]('SHA1',#ReportDefinitionForLookup))
Where #ReportDefinitionHash is int, and #ReportDefinitionForLookup is the varchar
Passing a simple char like 'test' produces a different int with my UDF than a normal call to HashBytes would produce.
Any advice on this issue?
If you can't create a function and have to use something that already exists in the DB:
sys.fn_repl_hash_binary
can be made to work using the syntax:
sys.fn_repl_hash_binary(cast('some really long string' as varbinary(max)))
Taken from: http://www.sqlnotes.info/2012/01/16/generate-md5-value-from-big-data/
Just use this function (taken from Hashing large data strings with a User Defined Function):
create function dbo.fn_hashbytesMAX
( #string nvarchar(max)
, #Algo varchar(10)
)
returns varbinary(20)
as
/************************************************************
*
* Author: Brandon Galderisi
* Last modified: 15-SEP-2009 (by Denis)
* Purpose: uses the system function hashbytes as well
* as sys.fn_varbintohexstr to split an
* nvarchar(max) string and hash in 8000 byte
* chunks hashing each 8000 byte chunk,,
* getting the 40 byte output, streaming each
* 40 byte output into a string then hashing
* that string.
*
*************************************************************/
begin
declare #concat nvarchar(max)
,#NumHash int
,#HASH varbinary(20)
set #NumHash = ceiling((datalength(#string)/2)/(4000.0))
/* HashBytes only supports 8000 bytes so split the string if it is larger */
if #NumHash>1
begin
-- # * 4000 character strings
;with a as (select 1 as n union all select 1) -- 2
,b as (select 1 as n from a ,a a1) -- 4
,c as (select 1 as n from b ,b b1) -- 16
,d as (select 1 as n from c ,c c1) -- 256
,e as (select 1 as n from d ,d d1) -- 65,536
,f as (select 1 as n from e ,e e1) -- 4,294,967,296 = 17+ TRILLION characters
,factored as (select row_number() over (order by n) rn from f)
,factors as (select rn,(rn*4000)+1 factor from factored)
select #concat = cast((
select right(sys.fn_varbintohexstr
(
hashbytes(#Algo, substring(#string, factor - 4000, 4000))
)
, 40) + ''
from Factors
where rn <= #NumHash
for xml path('')
) as nvarchar(max))
set #HASH = dbo.fn_hashbytesMAX(#concat ,#Algo)
end
else
begin
set #HASH = convert(varbinary(20), hashbytes(#Algo, #string))
end
return #HASH
end
And the results are as following:
select
hashbytes('sha1', N'test') --native function with nvarchar input
,hashbytes('sha1', 'test') --native function with varchar input
,dbo.fn_hashbytesMAX('test', 'sha1') --Galderisi's function which casts to nvarchar input
,dbo.fnGetHash('sha1', 'test') --your function
Output:
0x87F8ED9157125FFC4DA9E06A7B8011AD80A53FE1
0xA94A8FE5CCB19BA61C4C0873D391E987982FBBD3
0x87F8ED9157125FFC4DA9E06A7B8011AD80A53FE1
0x00000000AE6DBA4E0F767D06A97038B0C24ED720662ED9F1
I've taken the accepted answer, and modified it a bit with the following improvements:
no longer recursive function
now schema bound
no longer relying on undocumented stored procedures
two versions: one for nvarchar, one for varchar
returns same data size as HASHBYTES, leaving it up to the end user to convert to smaller based on algorithm used. This allows the functions to support future algorithms with larger data returns.
With these changes, the functions can now be used in persisted computed columns as they are now marked deterministic when created.
CREATE FUNCTION dbo.fnHashBytesNVARCHARMAX
(
#Algorithm VARCHAR(10),
#Text NVARCHAR(MAX)
)
RETURNS VARBINARY(8000)
WITH SCHEMABINDING
AS
BEGIN
DECLARE #NumHash INT;
DECLARE #HASH VARBINARY(8000);
SET #NumHash = CEILING(DATALENGTH(#Text) / (8000.0));
/* HashBytes only supports 8000 bytes so split the string if it is larger */
WHILE #NumHash > 1
BEGIN
-- # * 4000 character strings
WITH a AS
(SELECT 1 AS n UNION ALL SELECT 1), -- 2
b AS
(SELECT 1 AS n FROM a, a a1), -- 4
c AS
(SELECT 1 AS n FROM b, b b1), -- 16
d AS
(SELECT 1 AS n FROM c, c c1), -- 256
e AS
(SELECT 1 AS n FROM d, d d1), -- 65,536
f AS
(SELECT 1 AS n FROM e, e e1), -- 4,294,967,296 = 17+ TRILLION characters
factored AS
(SELECT ROW_NUMBER() OVER (ORDER BY n) rn FROM f),
factors AS
(SELECT rn, (rn * 4000) + 1 factor FROM factored)
SELECT #Text = CAST
(
(
SELECT CONVERT(VARCHAR(MAX), HASHBYTES(#Algorithm, SUBSTRING(#Text, factor - 4000, 4000)), 1)
FROM factors
WHERE rn <= #NumHash
FOR XML PATH('')
) AS NVARCHAR(MAX)
);
SET #NumHash = CEILING(DATALENGTH(#Text) / (8000.0));
END;
SET #HASH = CONVERT(VARBINARY(8000), HASHBYTES(#Algorithm, #Text));
RETURN #HASH;
END;
CREATE FUNCTION dbo.fnHashBytesVARCHARMAX
(
#Algorithm VARCHAR(10),
#Text VARCHAR(MAX)
)
RETURNS VARBINARY(8000)
WITH SCHEMABINDING
AS
BEGIN
DECLARE #NumHash INT;
DECLARE #HASH VARBINARY(8000);
SET #NumHash = CEILING(DATALENGTH(#Text) / (8000.0));
/* HashBytes only supports 8000 bytes so split the string if it is larger */
WHILE #NumHash > 1
BEGIN
-- # * 4000 character strings
WITH a AS
(SELECT 1 AS n UNION ALL SELECT 1), -- 2
b AS
(SELECT 1 AS n FROM a, a a1), -- 4
c AS
(SELECT 1 AS n FROM b, b b1), -- 16
d AS
(SELECT 1 AS n FROM c, c c1), -- 256
e AS
(SELECT 1 AS n FROM d, d d1), -- 65,536
f AS
(SELECT 1 AS n FROM e, e e1), -- 4,294,967,296 = 17+ TRILLION characters
factored AS
(SELECT ROW_NUMBER() OVER (ORDER BY n) rn FROM f),
factors AS
(SELECT rn, (rn * 8000) + 1 factor FROM factored)
SELECT #Text = CAST
(
(
SELECT CONVERT(VARCHAR(MAX), HASHBYTES(#Algorithm, SUBSTRING(#Text, factor - 8000, 8000)), 1)
FROM factors
WHERE rn <= #NumHash
FOR XML PATH('')
) AS NVARCHAR(MAX)
);
SET #NumHash = CEILING(DATALENGTH(#Text) / (8000.0));
END;
SET #HASH = CONVERT(VARBINARY(8000), HASHBYTES(#Algorithm, #Text));
RETURN #HASH;
END;
You could write a SQL CLR function:
[Microsoft.SqlServer.Server.SqlFunction]
public static SqlBinary BigHashBytes(SqlString algorithm, SqlString data)
{
var algo = HashAlgorithm.Create(algorithm.Value);
var bytes = Encoding.UTF8.GetBytes(data.Value);
return new SqlBinary(algo.ComputeHash(bytes));
}
And then it can be called in SQL like this:
--these return the same value
select HASHBYTES('md5', 'test stuff')
select dbo.BigHashBytes('md5', 'test stuff')
The BigHashBytes is only necessary if the length would be over 8k.
tested and working
select master.sys.fn_repl_hash_binary(someVarbinaryMaxValue)
moreover not complicated :)
This can be used as function body, too:
DECLARE #A NVARCHAR(MAX) = N'test'
DECLARE #res VARBINARY(MAX) = 0x
DECLARE #position INT = 1
,#len INT = DATALENGTH(#A)
WHILE 1 = 1
BEGIN
SET #res = #res + HASHBYTES('SHA2_256', SUBSTRING(#A, #position, 4000))
SET #position = #position+4000
IF #Position > #len
BREAK
END
SELECT HASHBYTES('SHA2_256',#res)
The idea si to HASH each 4000 part of the NVARCHAR(MAX) string and concatanate the results. Then to HASH the latter result.
It seems the easiest solution is to write a recursive hashing algorithm that parses the input text value into sub varchar(8000) segments.
I arbitrarily chose to slice the input string into 7500 character segments
The hashing algorithm returns a varbinary(20) which can easily be converted into a varchar(20)
ALTER FUNCTION [dbo].[BigHash]
(
#TextValue nvarchar(max)
)
RETURNS varbinary(20)
AS
BEGIN
if #TextValue = null
return hashbytes('SHA1', 'null')
Declare #FirstPart as varchar(7500)
Declare #Remainder as varchar(max)
Declare #RemainderHash as varbinary(20)
Declare #BinaryValue as varbinary(20)
Declare #TextLength as integer
Set #TextLength = len(#TextValue)
if #TextLength > 7500
Begin
Set #FirstPart = substring(#TextValue, 1, 7500)
Set #Remainder = substring(#TextValue, 7501, #TextLength - 7500)
Set #RemainderHash = dbo.BigHash(#Remainder)
Set #BinaryValue = hashbytes('SHA1', #FirstPart + convert( varchar(20), #RemainderHash, 2 ))
return #BinaryValue
End
else
Begin
Set #FirstPart = substring(#TextValue, 1, #TextLength)
Set #BinaryValue = hashbytes('SHA1', #FirstPart)
return #BinaryValue
End
return null
END
I'm working on a project involving C# and a SQL Server 2008 database.
In one of the tables, I have a field (nvarchar(15)) which will contain an IP address.
I'd like to add a check constraint which will validate that the input value is actually an IP address.
I wanted to use a regex to do that, but it seems that this feature is not supported by default. I saw things about writing a customm dll with UDF inside (MSDN tutorial), but I don't really understand how it works (i.e. where should I place the dll ?)
Is there a "simple" way to add such a constraint ?
Any solution is welcome.
Thanks in advance !
There are several way of doing this - the most performant one would probably be a CLR function in the database.
This is because SQL has fairly poor text manipulation tooling and no native RegEx in SQL Server.
As other have said, this is better handled by an application before insertion to the DB.
It shouldn't be handled in the database, it should be handled first and foremost in the application.
There's no harm in then adding a check to the database, but leaving it up to the DB to filter input is very sketchy.
The easiest way I can think of is to create a function like fnCheckIP and use this function in the constraint.
There's no need to use UDF.
create function fnCheckIP(#ip varchar(15)) returns bit
AS
begin
if (#ip is null)
return null
declare #num1 int
declare #num varchar(15)
declare #pos int
while (#ip is not null)
begin
set #pos = IsNull(NullIf(charindex('.', #ip), 0), Len(#ip) + 1)
set #num = substring(#ip, 1, #pos - 1)
if (isnumeric(#num) = 0) or (not cast(#num as int) between 0 and 255)
return cast(0 as bit)
if (len(#ip) - #pos <= 0)
set #ip = null
else
set #ip = NullIf(substring(#ip, #pos + 1, len(#ip) - #pos), '')
end
return cast (1 as bit)
end
go
select dbo.fnCheckIP('127.0.0.1')
select dbo.fnCheckIP('127.0.0.300')
This solution is similar to Paulo's but using either approach will require getting rid of the comma character because isnumeric allows commas which will throw a cast to int error.
CREATE FUNCTION fn_ValidateIP
(
#ip varchar(255)
)
RETURNS int
AS
BEGIN
DECLARE #Result int = 0
IF
#ip not like '%,%' and
len(#ip) <= 15 and
isnumeric(PARSENAME(#ip,4)) = 1 and
isnumeric(PARSENAME(#ip,3)) = 1 and
isnumeric(PARSENAME(#ip,2)) = 1 and
isnumeric(PARSENAME(#ip,1)) = 1 and
cast(PARSENAME(#ip,4) as int) between 1 and 255 and
cast(PARSENAME(#ip,3) as int) between 0 and 255 and
cast(PARSENAME(#ip,2) as int) between 0 and 255 and
cast(PARSENAME(#ip,1) as int) between 0 and 255
set #Result = 1
ELSE
set #Result = 0
RETURN #Result
END
select dbo.fn_ValidateIP('127.0.0.1')
This may not be entirely practical, but one way would be to store the converted string ###-###-###-### into a binary(4) data type. Let the interface fuss around with hyphens and deal with converting the four numbers to binary and back (and this could probably even be done by a caluclated column.) A bit extreme, yes, but with binary(4) you will always be able to turn it into an IP address.
At last about 10 yrs after Oracle, sqlserver got native compilation (with limitations)
ALTER function fn_ValidateIPv4
(
#ip varchar(255)
)
RETURNS int
--WITH EXECUTE AS OWNER, SCHEMABINDING, NATIVE_COMPILATION
AS
BEGIN
--ATOMIC WITH (TRANSACTION ISOLATION LEVEL = SNAPSHOT, LANGUAGE = N'us_english')
/* only sql2016 native Compilation **/
DECLARE #len_ip as int;
SET #len_ip = len(#ip);
DECLARE #firstBlock varchar(4) = '';
DECLARE #secondBlock varchar(4) = '';
DECLARE #thirdBlock varchar(4) = '';
DECLARE #fourthBlock varchar(4) = '';
DECLARE #countDot as smallint = 0;
DECLARE #l_i as smallint = 0;
DECLARE #l_curChar varchar(1) = 'X';
DECLARE #Result int = 0
IF (#len_ip <= 15)
BEGIN
WHILE (#l_i < #len_ip)
BEGIN
set #l_i += 1;
set #l_curChar = substring(#ip,#l_i,1);
if #l_curChar = '.'
SET #countDot += 1
ELSE
BEGIN
IF #l_curChar IN ( '0','1','2','3','4','5','6','7','8','9' )
BEGIN
IF #countDot = 0
SET #firstBlock = #firstBlock + #l_curChar;
IF #countDot = 1
SET #secondBlock = #secondBlock + #l_curChar;
IF #countDot = 2
SET #thirdBlock = #thirdBlock + #l_curChar;
IF #countDot = 3
SET #fourthBlock = #fourthBlock + #l_curChar;
IF #countDot > 3
set #firstBlock = 'AAA'; -- force error
END
ELSE set #firstBlock = 'AAA'; -- force error
END;
END;
IF ( #countDot = 3 and
cast(#fourthBlock as int) between 1 and 255 and
cast(#thirdBlock as int) between 0 and 255 and
cast(#secondBlock as int) between 0 and 255 and
cast(#firstBlock as int) between 0 and 255
)
set #Result = 1;
END;
/*
select dbo.fn_ValidateIPv4( '127.0.0.258' );
*/
RETURN #Result
END;
I had to remove not de-supported built functions isnumeric etc...
I have a table with two columns: price (int) and price_display (varchar).
price is the actual numerical price, e.g. "9990"
price_display is the visual representation, e.g. "$9.99" or "9.99Fr"
I've been able to confirm the two columns match via regexp:
price_display not regexp
format(price/1000, 2)
But in the case of a mismatch, I want to extract the value from the price_display column and set it into the price column, all within the context of an update statement. I've not been able to figure out how.
Thanks.
This function does the job of only returning the digits 0-9 from the string, which does the job nicely to solve your issue, regardless of what prefixes or postfixes you have.
http://www.artfulsoftware.com/infotree/queries.php?&bw=1280#815
Copied here for reference:
SET GLOBAL log_bin_trust_function_creators=1;
DROP FUNCTION IF EXISTS digits;
DELIMITER |
CREATE FUNCTION digits( str CHAR(32) ) RETURNS CHAR(32)
BEGIN
DECLARE i, len SMALLINT DEFAULT 1;
DECLARE ret CHAR(32) DEFAULT '';
DECLARE c CHAR(1);
IF str IS NULL
THEN
RETURN "";
END IF;
SET len = CHAR_LENGTH( str );
REPEAT
BEGIN
SET c = MID( str, i, 1 );
IF c BETWEEN '0' AND '9' THEN
SET ret=CONCAT(ret,c);
END IF;
SET i = i + 1;
END;
UNTIL i > len END REPEAT;
RETURN ret;
END |
DELIMITER ;
SELECT digits('$10.00Fr');
#returns 1000
One approach would be to use REPLACE() function:
UPDATE my_table
SET price = replace(replace(replace(price_display,'Fr',''),'$',''),'.','')
WHERE price_display not regexp format(price/1000, 2);
This works for the examples data you gave:
'$9.99'
'9.99Fr'
Both result in 999 in my test. With an update like this, it's important to be sure to back up the database first, and be cognizant of the formats of the items. You can see all the "baddies" by doing this query:
SELECT DISTINCT price_display
FROM my_table
WHERE price_display not regexp format(price/1000, 2)
ORDER BY price_display;
For me CASTING the field did the trick:
CAST( price AS UNSIGNED ) // For positive integer
CAST( price AS SIGNED ) // For negative and positive integer
IF(CAST(price AS UNSIGNED)=0,REVERSE(CAST(REVERSE(price) AS UNSIGNED)),CAST(price AS UNSIGNED)) // Fix when price starts with something else then a digit
For more details see:
https://dev.mysql.com/doc/refman/5.0/en/cast-functions.html
This is a "coding horror", relational database schemas should NOT be written like this!
Your having to write complex and unnecessary code to validate the data.
Try something like this:
SELECT CONCAT('$',(price/1000)) AS Price FROM ...
In addition, you can use a float, double or real instead of a integer.
If you need to store currency data, you might consider adding a currency field or use the systems locale functions to display it in the correct format.
I create a procedure that detect the first number in a string and return this, if not return 0.
DROP FUNCTION IF EXISTS extractNumber;
DELIMITER //
CREATE FUNCTION extractNumber (string1 VARCHAR(255)) RETURNS INT(11)
BEGIN
DECLARE position, result, longitude INT(11) DEFAULT 0;
DECLARE string2 VARCHAR(255);
SET longitude = LENGTH(string1);
SET result = CONVERT(string1, SIGNED);
IF result = 0 THEN
IF string1 REGEXP('[0-9]') THEN
SET position = 2;
checkString:WHILE position <= longitude DO
SET string2 = SUBSTR(string1 FROM position);
IF CONVERT(string2, SIGNED) != 0 THEN
SET result = CONVERT(string2, SIGNED);
LEAVE checkString;
END IF;
SET position = position + 1;
END WHILE;
END IF;
END IF;
RETURN result;
END //
DELIMITER ;
Return last number from the string:
CREATE FUNCTION getLastNumber(str VARCHAR(255)) RETURNS INT(11)
DELIMETER //
BEGIN
DECLARE last_number, str_length, position INT(11) DEFAULT 0;
DECLARE temp_char VARCHAR(1);
DECLARE temp_char_before VARCHAR(1);
IF str IS NULL THEN
RETURN -1;
END IF;
SET str_length = LENGTH(str);
WHILE position <= str_length DO
SET temp_char = MID(str, position, 1);
IF position > 0 THEN
SET temp_char_before = MID(str, position - 1, 1);
END IF;
IF temp_char BETWEEN '0' AND '9' THEN
SET last_number = last_number * 10 + temp_char;
END IF;
IF (temp_char_before NOT BETWEEN '0' AND '9') AND
(temp_char BETWEEN '0' AND '9') THEN
SET last_number = temp_char;
END IF;
SET position = position + 1;
END WHILE;
RETURN last_number;
END//
DELIMETER;
Then call this functions:
select getLastNumber("ssss111www222w");
print 222
select getLastNumber("ssss111www222www3332");
print 3332