How would you decode a hex string to get the value in text format by using a select statement?
For example my data in hex is:
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
I want to decode it to get the string value using a select statement.
The value of the above is "ONLY FOR BACK-UP ON LEVEL ONE FOR CRANES"
what I have tried is :
SELECT CAST('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'
AS VARCHAR(30000) CCSID 37) from myschema.atable
The above sql returns the exact same hex string and not the decoded text string of "ONLY FOR BACK-UP ON LEVEL ONE FOR CRANES" what I expected.
Is it possible to do this with a cast? If it is what will the syntax be?
My problem that I have is a system stores text data in a blob field and I want to use a select statement to see what the text data is in the blob field.
Db : Db2 on Ibm
Edit:
I have managed to covert the string to the hex value by using :
select hex(cast('ONLY FOR BACK-UP ON LEVEL ONE FOR CRANES' as varchar(100) ccsid 1208))
FROM myschema.atable
This gives me the string in hex :
4F4E4C5920464F52204241434B2D5550204F4E204C4556454C204F4E4520464F52204352414E4553
Now somehow I need to do the inverse and get the value.
Thanks.
Edit
Using the answer from Daniel Lema, I tried using the unhex function but my result that I got was :
|+<ßã|êâ ä.í&|+<áîá<|+áã|êäê +áë
Is this something to do with a CSSID? Or how should I convet the above to a readable string?
This is the table field definition if it will help the field with my data in is GDTXFT a BLOB :
I was able to take your shortened hex string and convert is to a valid EBCDIC string.
The problem I ran into is that the original hex code you receive comes in UTF-16LE (Thanks Tom Blodget). IBM's CCSID system does not have a distinction between UTF-16BE and UTF-16LE so I am at a loss there on how to convert it properly.
If it is in UTF-8 as you generated later, the following would work for you. It's not the prettiest but throw it in a couple functions and it will work.
Create or replace function unpivothex (in_ varchar(30000))
returns table (Hex_ char(2), Position_ int)
return
with returnstring (ST , POS )
as
(Select substring(STR,1,2), 1
from table(values in_) as A(STR)
union all
Select nullif(substring(STR,POS+2,2),'00'), POS+2
from returnstring, table(values in_) as A(STR)
where POS+2 <= length(in_)
)
Select ST, POS
from returnstring
;
Create or replace function converthextostring
(in_string char(30000))
returns varchar(30000)
return
(select listagg(char(varbinary_format(B.Hex_),1)) within group(order by In_table.Position_)
from table(unpivothex(upper(in_string))) in_table
join table(unpivothex(hex(cast('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz ' as char(53) CCSID 1208)))) A on In_table.Hex_ = A.Hex_
join table(unpivothex(hex(cast('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz ' as char(53) CCSID 37)))) B on A.Position_ = B.Position_
);
Here is a version if you're not on at least V7R2 TR6 or V7R3 TR2.
Create or replace function converthextostring
(in_string char(30000))
returns varchar(30000)
return
(select xmlserialize(
xmlagg(
xmltext(cast(char(varbinary_format(B.Hex_),1) as char(1) CCSID 37))
order by In_table.Position_)
as varchar(30000))
from table(unpivothex(upper(in_string))) in_table
join table(unpivothex(hex(cast('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz ' as char(53) CCSID 1208)))) A on In_table.Hex_ = A.Hex_
join table(unpivothex(hex(cast('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz ' as char(53) CCSID 37)))) B on A.Position_ = B.Position_
);
I tried the following solution I found published by Marcin Rudzki at Convert HEX value to CHAR on DB2, tested in my own Db2 for LUW v11 with a small modification.
the solution consists on creating a function just as Marcin suggested:
CREATE FUNCTION unhex(in VARCHAR(32000) FOR BIT DATA)
RETURNS VARCHAR(32000)
LANGUAGE SQL
CONTAINS SQL
DETERMINISTIC NO EXTERNAL ACTION
BEGIN ATOMIC
RETURN in;
END
To test the solution, lets create an HEXSAMPLE table with a HEXSTRING column loaded with the string representation of a HEX sequence:
INSERT INTO HEXSAMPLE (HEXSTRING) VALUES ('4F4E4C5920464F52204241434B2D5550204F4E204C4556454C204F4E4520464F52204352414E4553')
Then exec the following query (and here it is different from the original proposal):
SELECT UNHEX(CAST(HEXTORAW(HEXSTRING) AS VARCHAR(2000) FOR BIT DATA)) as TEXT, HEXSTRING FROM HEXSAMPLE
With result:
TEXT HEXSTRING
---------------------------------------- --------------------------------------------------------------------------------
ONLY FOR BACK-UP ON LEVEL ONE FOR CRANES 4F4E4C5920464F52204241434B2D5550204F4E204C4556454C204F4E4520464F52204352414E4553
I hope someone else can find a more direct solution. Also, if someone can explain why it works, it will be very interesting.
I question why you need to do this...
There's valid reasons to convert a hex string back to it's character equivalent...for instance somebody sends you a 32 byte string UUID and you want it back it it's 16 byte binary form.
But there's no reason ONLY FOR BACK-UP ON LEVEL ONE FOR CRANES should have been transformed to hex.
I suspect you need to post a new question asking why you're not getting readable strings in the first place.
However, in answer to this question... IBM i has an MI function Convert Character to Hex (CVTCH) that is easily called from any ILE langage. You could wrap that function call up into a user defined function in order to use it from SQL.
Note that you'll need to know what the hex string represents, EBCDIC, ASCII or Unicode, because you'll need to be able to tell the system what you've started with. From there there are ways to convert between encoding.
Here's an article that shows how to call the MI function from RPG.
Utilizing MI Functions in RPG Programs
A more modern free form version of the prototype that takes advantage of enhancements to the CCSID keyword might look like
dcl-pr FromHex extproc('cvtch');
charString char(32767) ccsid(*UTF8) options(*varsize);
hexString char(65534) ccsid(*HEX) const options(*varsize);
hexStringLen int(10) value;
end-pr;
With the above prototype, the system will treat the character string that comes back as UTF8 (ccsid 1208). But all I'm doing is telling the system how to interpret the bytes that come back. If the string was actually EBCDIC, I'm going to get garbage.
I think you could even defined the cvtch function directly as an external UDF without needing an ILE wrapper. I'd have to play around with that...
Disregard that idea...cvtch only has parameters, not a return value. Using an ILE wrapper is the best way to move the output parameter to a return value for use as a UDF.
The problem is that your original string is in ASCII format (actually with x'00' byte after each letter), and you have to convert it to EBCDIC.
Below is the solution for latin capital letters only:
select cast(translate(replace(mycol, x'00', x'')
, x'C1C2C3C4C5C6C7C8C9D1D2D3D4D5D6D7D8D9E2E3E4E5E6E7E8E940'
, x'4142434445464748494A4B4C4D4E4F505152535455565758595A20'
) as varchar(500) ccsid 37)
from mytab;
Every ASCII character is translated to the corresponding EBCDIC one.
x'00' symbols are removed.
cast (col_name as varchar(2000) ccsid ascii for sbcs data)
Related
I have data stored in a column in my SQL Server table like the following:
0x003600380032003200330031002D003400
I know the output for this should be:
682231-4
Can someone help me with the SQL code for the conversion?
Something like:
select converttochar (0x003600380032003200330031002D003400)
Returns: 682231-4
I'm not sure if I am looking at hex or binary conversion or what....
It is difficult to see what the exact encoding issue is based on the sample data.
I imagine Larnu is correct and this is just UCS-2 encoded data that for some reason has had a leading null byte added.
Another interpretation is that this is UCS-2 encoded data encoded with a different endianess - so each double byte needs to be reversed (though then there is still a surplus null byte at the end).
As long as each alternate byte is 0x00 it doesn't much matter which case is correct. To strip out the null bytes and cast to varchar you can also use
SELECT REPLACE(0x003600380032003200330031002D003400, 0x00, '' COLLATE Latin1_General_Bin)
For the limited character set shown in the question these will all have the same effect. If the raw data can have non ASCII characters this approach will likely fall down.
This actually looks like you have an nvarchar with a leading 00 at the start. This is messy, but would work:
SELECT CONVERT(nvarchar(30),CONVERT(varbinary(60),STUFF(CONVERT(VARCHAR(60), 0x003600380032003200330031002D003400,1),3,2,''),1));
This strips out the leading 00 characters, making the value 0x3600380032003200330031002D003400, which is the nvarchar value for N'682231-4'.
It strips the value out by converting the varbinary to a varchar but using the style code 1, this means you have a varchar with the value '0x3600380032003200330031002D003400'; allowing you to perform string manipulations. Then I use STUFF to remove the character and CONVERT with style code 1 to make it a varbinary again.
DB<>Fiddle
Alternatively, you could remove all the null character tuples and convert. This looks way messier as you can't just blanket replace '00' (or rather I don't feel it's "safe" to), so I put the characters into their tuples, and rebuild:
DECLARE #YourBinary varbinary(60) = 0x003600380032003200330031002D003400;
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT TOP(60) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I
FROM N N1, N N2, N N3)
SELECT CONVERT(varchar(60),CONVERT(varbinary(60),(SELECT V.SS + ''
FROM Tally T
CROSS APPLY(VALUES(SUBSTRING(CONVERT(varchar(60),#YourBinary,1),(T.I*2)+1,2)))V(SS)
WHERE V.SS NOT IN ('00','')
FOR XML PATH(''),TYPE).value('.','varchar(60)'),1));
This idea might be better though, if some of your values have a leading 00 and others don't. Of course, this solution also assumes the end value is a varchar, not an nvarchar.
SELECT CONVERT(VARCHAR(60), 0x003600380032003200330031002D003400);
Demo
I had also same issue some ago and the used the below statement for convert and my problem resolved that time ..
SELECT CONVERT(VARCHAR(60), 0x003600380032003200330031002D003400);
Please try to run this and see whether your problem is resolved or not?
When searching for a string in our database where the column is of type nvarchar, specifying the 'N' prefix in the query nets some results. Leaving it out does not. I am trying the search for a Simplified Chinese string in a database that previously did not store any Chinese strings yet.
The EntityFramework application that uses the database, correctly retrieves the strings and the LINQ queries also work in the application. However, in SQL Server 2014 Management Studio, when I do a an SQL query for the string it does not show up unless I specify the 'N' prefix for unicode. (Even though the column is nvarchar type)
Works:
var text = from asd in Translations.TranslationStrings
where asd.Text == "嗄法吖无上几"
select asd;
MessageBox.Show(text.FirstOrDefault().Text);
Does not work:
SELECT *
FROM TranslationStrings
where Text = '嗄法吖无上几'
If I prefix the Chinese characters with 'N' it works.
Works:
SELECT *
FROM TranslationStrings
where Text = N'嗄法吖无上几'
Please excuse the Chinese characters, I just typed something random. My question is, is there something I can do to not have to include the 'N' prefix when doing a query?
Thank you very much!
As #sworkalot has mentioned below:
The default for .Net is Unicode, that's why you don't need to specify
it. This is not the case for Sql Manager.
If not specified Sql will assume that you work with asci according to
the collation specified in your DB.
Hence, when working from Sql Server you need to use N'
https://sqlquantumleap.com/2018/09/28/native-utf-8-support-in-sql-server-2019-savior-false-prophet-or-both/
Check out these examples, pay close attention to the data types and the values being assigned:
DECLARE #Varchar VARCHAR(100) = '嗄'
DECLARE #VarcharWithN VARCHAR(100) = N'嗄' -- Has N prefix
DECLARE #NVarchar NVARCHAR(100) = '嗄'
DECLARE #NVarcharWithN NVARCHAR(100) = N'嗄' -- Has N prefix
SELECT
Varchar = #Varchar,
VarcharWithN = #VarcharWithN,
NVarchar = #NVarchar,
NVarcharWithN = #NVarcharWithN
SELECT
Varchar = CONVERT(VARBINARY, #Varchar),
VarcharWithN = CONVERT(VARBINARY, #VarcharWithN),
NVarchar = CONVERT(VARBINARY, #NVarchar),
NVarcharWithN = CONVERT(VARBINARY, #NVarcharWithN)
Results:
Varchar VarcharWithN NVarchar NVarcharWithN
? ? ? 嗄
Varchar VarcharWithN NVarchar NVarcharWithN
0x3F 0x3F 0x3F00 0xC455
NVARCHAR data type stores 2 bytes for each character while VARCHAR only stores 1 (you can see this on the VARBINARY cast on the 2nd SELECT). Since chinese characters representation need 2 bytes to be stored, you have to use NVARCHAR to store them. If you try to stuff them in a VARCHAR it will be stored as ? and you will lose the original character information. This also happens on the 3rd example, because the literal doesn't have the N so it's converted to VARCHAR before actually assigning the value to the variable.
It's because of this that you need to add the N prefix when typing these characters as literals, so the SQL engine knows that you are typing characters that need 2 byte representation. So if you are doing a comparison against a NVARCHAR column always add the N prefix. You can change the database collation, but it's recommended to always use the proper data type independent of the collation so you don't have problems when using coding on different databases.
If you could explain the reason why you want to omit the N prefix we might address that, although I believe there is no work around in this particular case.
The default for .Net is Unicode, that's why you don't need to specify it.
This is not the case for Sql Manager.
If not specified Sql will assume that you work with asci according to the collation specified in your DB.
Hence, when working from Sql Server you need to use N'
https://sqlquantumleap.com/2018/09/28/native-utf-8-support-in-sql-server-2019-savior-false-prophet-or-both/
Is there a way to get a number formatted with a comma for thousand in numbers?
According to IBM documentation, this is the syntax:
DECIMAL(:newsalary, 9, 2, ',')
newsalary is the string (field)
9 is the precision
2 is the scale
, is the delimiter.
I tried:
SELECT DECIMAL ( T1.FIELD1 , 15 , 2 , "," ) AS TOTAL FROM TABLE T1
When trying it, I am getting the following error:
Message: [SQL0171] Argument 4 of function DECIMAL not valid.
DECIMAL converts from string type to a numeric type.
Numeric types don't have separators; only character representations of numbers have separators.
What tool are you using STRSQL, Run SQL Scripts or something else? Once you convert the string to a number, the tool should add the language appropriate separators when it displays the numeric data. For example, in STRSQL:
select decimal('12345.67', 12,2) as mynum
from sysibm.sysdummy1
Returns:
MYNUM
12,345.67
Using SQL to format strings is usually a bad idea. That should be left to whatever is consuming the data.
But if you really, really, really want to do it. You should create a user defined function (UDF) that does it for you. Here's an article, Make SQL Edit the Way You Want It To that includes source for for an EDITDEC function written in ILE RPG along with the SQL function definition you need to use it in an SQL statement.
I'm trying to find and replace very long HTML text in a SQL Server temp table (I'm using SQL Server 2012).
The query structure is:
UPDATE #Descriptions
SET Desc1 = replace(Desc1, 'VERY LONG HTML 1','VERY LONG HTML 2')
WHERE Desc1 like 'VERY LONG HTML 1'
I'm getting
Text or binary data will be truncated
error. The HTML parts are long, but should fit easily - whole thing fits in varchar(max) and these are only parts of it.
Can anyone help please?
Thank you!
M.
try using this :
field = replace(cast(field as varchar(max)),'string' ,'replacement')
As Sean Lange pointed out it's because of output string being truncated. This can be found in official documentation:
Return Types
Returns nvarchar if one of the input arguments is of the nvarchar data type; otherwise, REPLACE returns varchar. Returns
NULL if any one of the arguments is NULL. If string_expression is not
of type varchar(max) or nvarchar(max), REPLACE truncates the return
value at 8,000 bytes. To return values greater than 8,000 bytes,
string_expression must be explicitly cast to a large-value data type.
This can be workarounded by splitting your string into multiple string of fixed length, replacing data in there and then concatenating them back together.
In table I have string column which contains a hex value. For example value '000000000000000a' means 10. Now I need to process bitand operation: bitand(tableName.hexColumn, ?). When I read the Informix specification of this function it needs 2 int. So my question is: what is the simpler way to process this operation?
PS: Probably there is no solution in Informix so I will have to create my own bitandhexstring function where input will be 2 string and hex form but I have no idea where to start.
There are a variety of issues to be dealt with:
Your hex string has 16 digits, so the values are presumably (in general) 64-bit quantities. That means you need to be sure that the BITAND function has a variant that handles BIGINT (or perhaps INT8 — I'm not going to mention INT8 again, but it is nominally an option when BIGINT is mentioned) data.
You need to convert your hex string to a BIGINT.
It is not clear whether you'll need to convert the result BIGINT back to a hex string.
Some testing with Informix 11.70.FC6 on Mac OS X 10.10.4 shows that BITAND is safe with 64-bit numbers. That's good news!
The HEX function, when passed a BIGINT, returns a CHAR(20) string that starts with 0x and contains a hex representation of the number, so that more or less addresses point 3. The residual issue is 'how to convert 16-byte strings of hex digits to a BIGINT value'. Nominally, a cast operation like:
CAST('0xde3962e8c68a8001' AS BIGINT)
should do the job (but see below). There may be a better way of doing it than a brute-force and ignorance stored procedure, but I'm not immediately sure what it is.
Caveat Lector.
While testing this, I tried two queries:
SELECT bi, HEX(bi) FROM Test_BigInt;
SELECT bi, HEX(bi), SUBSTR(HEX(bi), 3, 16) FROM Test_BigInt;
on a table Test_BigInt with a single column bi of type BIGINT (not null, as it happened, but that's not material).
The first query worked fine. The type of the HEX(bi) expression was CHAR(20) and the values were like
0 0x0000000000000000
6898532535585831936 0x5fbc82ca87117c00
-2300268458811555839 0xe013ce0628808001
The second query sort of worked for small values of bi (0, 1, 2), but generated an error -1215: Value exceeds limit of INTEGER precision when the values got large. The problem is not the SUBSTR function directly. This was testing with Informix 11.70.FC6 on Mac OS X 10.10.4 — tested on 2015-07-08. The following pair of queries worked as expected (which is my justification for claiming that the problem is not in the SUBSTR function per se).
SELECT bi, HEX(bi) AS hex_bi FROM Test_BigInt INTO TEMP t;
SELECT bi, hex_bi, SUBSTR(hex_bi, 3, 16) FROM t;
It seems to be an interaction problem when the result of HEX is used in a string operation context. I first got the problem when trying to concatenate an empty string to the result of HEX: HEX(bi) || ''. That turns out to be unnecessary given that the result of HEX is reported as CHAR(20), but also indicates SUBSTR is not directly at fault.
I also tried CAST to get the hex string converted to BIGINT:
SELECT CAST('0xde3962e8c68a8001' AS BIGINT) FROM dual;
BIGINT
-964001791
SELECT HEX(CAST('0xde3962e8c68a8001' AS BIGINT)) FROM dual;
CHAR(18)
0xffffffffc68a8001
Grrr! Something is mishandling the conversion. This is not new software (well over 2 years old), but the chances are that unless someone else has spotted the bug, it has not yet been fixed, even in the latest version.
I've reported this through back-channels to IBM/Informix.
Stored procedures to convert hex string to BIGINT
CREATE PROCEDURE hexval(c CHAR(1)) RETURNING INTEGER;
RETURN INSTR("0123456789abcdef", lower(c)) - 1;
END PROCEDURE;
CREATE PROCEDURE hexstr_to_bigint(ival VARCHAR(18)) RETURNING bigint;
DEFINE oval DECIMAL(20,0);
DEFINE i,j,len INTEGER;
LET ival = LOWER(ival);
IF (ival[1,2] = '0x') THEN LET ival = ival[3,18]; END IF;
LET len = LENGTH(ival);
LET oval = 0;
FOR i = 1 TO len
LET j = hexval(SUBSTR(ival, i, 1));
LET oval = oval * 16 + j;
END FOR;
IF (oval > 9223372036854775807) THEN
LET oval = oval - 18446744073709551616;
END IF;
RETURN oval;
END PROCEDURE;
Casual testing:
execute procedure hexstr_to_bigint('000A');
10
execute procedure hexstr_to_bigint('FFff');
65535
execute procedure hexstr_to_bigint('FFFFffffFFFFffff');
-1
execute procedure hexstr_to_bigint('0XFFFFffffFFFFffff');
-1
execute procedure hexstr_to_bigint('000000000000000A');
10
Those values are correct.