using PARSENAME to find the last item in a list - sql

I am using Parsename in SQL and would like to extract the last element in a list of items. I am using the following code.
Declare #string as varchar(1000)
set #string = '25.26.27.28'
SELECT PARSENAME(#string, 1)
This works and returns the value 28 as I expect. However if I expand my list past more than 4 items then the result returns a NULL. For example:
Declare #string2 as varchar(1000)
set #string2 = '25.26.27.28.29'
SELECT PARSENAME(#string2, 1)
I would expect this to return a value of 29 however only NULL is returned
I'm sure there is a simple explaination to this can anyone help?

PARSENAME is designed specifically to parse an sql object name. The number of periods in the latter example exempt it from being such a name so the call correctly fails.
Instead
select right(#string2, charindex('.', reverse(#string2), 1) - 1)

PARSENAME ( 'object_name' , object_piece )
'object_name'
Is the name of the object for which to retrieve the specified object part.
This name can have four parts: the server name, the database name, the owner name, and the object name.
If we give more than 4 parts, it will always return null.
For Ref: http://msdn.microsoft.com/en-us/library/ms188006.aspx

Related

Needing to parse out data

I am trying to parse out certain data from a string and I am having issues.
Here is the string:
1=BETA.1.0^2=175^3=812^4=R^5=N^9=1^12=1^13=00032^14=REP NOT FOUND ON REP TABLE, CANNOT INSERT TO REPRGR.^10=107~117~265~1114~3143~3505~3506~3513~5717^11=SA16~1~WY~WY~A~S~20100210~001~SE62^-omitted due to existing Rep Not Found
I need to return this "REP NOT FOUND ON REP TABLE, CANNOT INSERT TO REPRGR."
Here is my query SELECT CONVERT(VARCHAR(5000),CHARINDEX('14=',Column))FROM Table
If you're parsing, can we assume that you don't know what might come after the '^14=', but you need to capture whatever does? So searching for a particular string won't work because anything could come after '^14='. The best approach is to identify the longest reliable specific string that gives you a "foothold" to find the data you're looking for. What you don't want to do is accidentally capture the wrong data if the '^14=' appears more than once in your string. It looks like the '^' is your delimiter, since I don't see one at the start of the string. So you were actually on the right track, you just need to use SUBSTRING as a commenter mentioned. You also need to identify a marker for the end of the error message, which looks like it might be the next occurring '^', correct? Check several samples to be sure of this, and make sure the end marker doesn't at any point exist before your start marker or you'll get an error.
SELECT CAST((SUBSTRING(Column,CHARINDEX('14=',Column,0),CHARINDEX('^',Column,CHARINDEX('14=',Column,0) + 1) - CHARINDEX('14=',Column,0))) AS VARCHAR(5000)) FROM Table
You may need to increment or decrement the start position and end position by doing a +1 or -1 to fully capture your error message. But this should dynamically grab any length error message provided you are positive of your starting and ending markers.
I also have here a table-valued parsing function, where you would pass it the string and the '^' and it will return a table of data with not only the 14=, but everything.
CREATE function [dbo].[fn_SplitStringByDelimeter]
(
#list nvarchar(8000)
,#splitOn char(1)
)
returns #rtnTable table
(
id int identity(1,1)
,value nvarchar(100)
)
as
begin
declare #index int
declare #string nvarchar(4000)
select #index = 1
if len(#list) < 1 or #list is null return
--
while #index!= 0
begin
set #index = charindex(#splitOn,#list)
if #index!=0
set #string = left(#list,#index - 1)
else
set #string = #list
if(len(#string)>0)
insert into #rtnTable(value) values(#string)
--
set #list = right(#list,len(#list) - #index)
if len(#list) = 0 break
end
return
end
It sounds like you're trying to get the value of argument 14. This should do it:
select substring(
someData
, charindex('^14=',someData) + 4
, charindex('^',someData, charindex('^14=',someData) + 4) - charindex('^14=',someData) - 4
) errorMessage
from myData
where charindex('^14=',someData) > 0
and charindex('^',someData, charindex('^14=',someData) + 4) > 0
Try it here: http://sqlfiddle.com/#!18/22f23/2
This gets a substring of the given input.
The substring starts at the first character after the string ^14=; i.e. we get the index of ^14= in the string, then add 4 to it to skip over the matched characters themselves.
The substring ends at the first ^ character after the one in ^14=. We get the index of that character, then subtract the starting position from it to get the length of the desired output.
Caveats: If there is no parameter (^) after ^14= this will not work. Equally if there is no ^14= (even if the string starts 14=) this will not work. From the information available that's OK; but if this is a concern please say and we can provide something to handle that more complex scenario.
Code to create table & populate demo data
create table myData (someData nvarchar(256))
insert myData (someData)
values ('1=BETA.1.0^2=175^3=812^4=R^5=N^9=1^12=1^13=00032^14=REP NOT FOUND ON REP TABLE, CANNOT INSERT TO REPRGR.^10=107~117~265~1114~3143~3505~3506~3513~5717^11=SA16~1~WY~WY~A~S~20100210~001~SE62^-omitted due to existing Rep Not Found')
, ('1xx^14=something else.^10=xx')
You could try to use a Case When statement with wildcards to find the value that you want.
Example:
SELECT
CASE
WHEN x LIKE '%REP Not Found%'
THEN 'REP NOT FOUND ON REP TABLE, CANNOT INSERT TO REPRGR'
ELSE
''
END AS x
FROM
#T1
You could use this query (assuming MySQL database):
-- item is the column that contains the string
select SUBSTR(item, LOCATE('REP',item), LOCATE('REPRGR.',item) + LENGTH('REPRGR.') - LOCATE('REP', item)) info_msg from Table;
Illustration:
create table parsetest (item varchar(5000));
insert into parsetest values('1=BETA.1.0^2=175^3=812^4=R^5=N^9=1^12=1^13=00032^14=REP NOT FOUND ON REP TABLE, CANNOT INSERT TO REPRGR.^10=107~117~265~1114~3143~3505~3506~3513~5717^11=SA16~1~WY~WY~A~S~20100210~001~SE62^-omitted due to existing Rep Not Found');
select * from parsetest;
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| item |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1=BETA.1.0^2=175^3=812^4=R^5=N^9=1^12=1^13=00032^14=REP NOT FOUND ON REP TABLE, CANNOT INSERT TO REPRGR.^10=107~117~265~1114~3143~3505~3506~3513~5717^11=SA16~1~WY~WY~A~S~20100210~001~SE62^-omitted due to existing Rep Not Found |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
select SUBSTR(item, LOCATE('REP',item), LOCATE('REPRGR.',item) + LENGTH('REPRGR.') - LOCATE('REP', item)) info_msg from parsetest;
+------------------------------------------------------+
| info_msg |
+------------------------------------------------------+
| REP NOT FOUND ON REP TABLE, CANNOT INSERT TO REPRGR. |
+------------------------------------------------------+

Extract e-mail address from string

I have table called Entities with the column CustomData.
I need to extract the email address from each row.
Also if value is null I need to to show as null.
Sample rows from CustomData:
Id CustomData Name
273 [{"Name":"Customer","Value":"test customer"},{"Name":"Address","Value":null},{"Name":"Email","Value":null},{"Name":"Company Name","Value":null},{"Name":"Other Phone","Value":null}] 2323123213
274 [{"Name":"Customer","Value":"Cash Sale"},{"Name":"Address","Value":null},{"Name":"Email","Value":"test#outlook.com"},{"Name":"Company Name","Value":null},{"Name":"Other Phone","Value":null}] 2222222222
This is the string i will be using to update my system.
I have previously achieved selecting the phone number form this same data but it was a fixed length. I can't seem to pull the e-mail address.
I will post a couple of the different methods I have tried so far once im back at my PC
Well, in such a denormalized data your only option is to parse it and try to get email. Most elegant way - is to use json parser, but it is not awailable in current versions of sql server, so you have to parse it manually.
Assuming each record for email starts with {"Name":"Email","Value":, you can do it in a few steps:
Find position of {"Name":"Email","Value": in your string.
Find first occurence of } in the right remainder of the string.
Get substring in between.
Check if it is string equals to 'null' - then return null, otherwise return string itself.
So it can be done like in this snippet:
declare #data nvarchar(max), #pattern nvarchar(max)
select #data = '[{"Name":"Customer","Value":"test customer"},
{"Name":"Address","Value":null},
{"Name":"Email","Value":null},
{"Name":"Company Name","Value":null},
{"Name":"Other Phone","Value":null}]'
select #pattern = '{"Name":"Email","Value":'
select nullif(substring(#data,
charindex(#pattern, #data, 0) + len(#pattern),
charindex('}', #data, charindex(#pattern, #data, 0))
- charindex(#pattern, #data, 0) - len(#pattern)
), 'null')

Charindex not working when using two variables

I'm using two cursors in SQL Server 2008 R2 to work with two lists of values returned from Select statements. I read the first value from list tofind1 into a variable find1 and a value from list tosearch1 into a variable search1.
The underlying variable types in the tables are nvarchar of length 10 and 255 respectively. The variables are defined as the same length nvarchar.
I'm testing it with two strings similar to this:
find1 = 'bill'
search1 = 'bill,fred,mary'
When I try charindex(find1, search1) it returns 0. This is incorrect.
When I try charindex('bill',search1) it returns 1. This is correct.
When I just run the following code, both pairs of statements work fine:
DECLARE #search1 nvarchar(255);
DECLARE #find1 nvarchar(10);
set #find1 = 'bill'
set #search1 = 'bill,fred,mary'
select charindex(#find1,#search1)
select charindex('bill','bill,fred,mary')
if 'bill,fred,mary' like '%bill%'
print 'Yay'
if #search1 like '%' + #find1 + '%'
print 'Yes'
Is there something about selecting values into a cursor then assigning it to a variable that messes with its data type so CHARINDEX and LIKE won't work? I've trying using CAST functions to triply make sure that the variables are all seen as nvarchar.

Looking for a scalar function to find the last occurrence of a character in a string

Table FOO has a column FILEPATH of type VARCHAR(512). Its entries are absolute paths:
FILEPATH
------------------------------------------------------------
file://very/long/file/path/with/many/slashes/in/it/foo.xml
file://even/longer/file/path/with/more/slashes/in/it/baz.xml
file://something/completely/different/foo.xml
file://short/path/foobar.xml
There's ~50k records in this table and I want to know all distinct filenames, not the file paths:
foo.xml
baz.xml
foobar.xml
This looks easy, but I couldn't find a DB2 scalar function that allows me to search for the last occurrence of a character in a string. Am I overseeing something?
I could do this with a recursive query, but this appears to be overkill for such a simple task and (oh wonder) is extremely slow:
WITH PATHFRAGMENTS (POS, PATHFRAGMENT) AS (
SELECT
1,
FILEPATH
FROM FOO
UNION ALL
SELECT
POSITION('/', PATHFRAGMENT, OCTETS) AS POS,
SUBSTR(PATHFRAGMENT, POSITION('/', PATHFRAGMENT, OCTETS)+1) AS PATHFRAGMENT
FROM PATHFRAGMENTS
)
SELECT DISTINCT PATHFRAGMENT FROM PATHFRAGMENTS WHERE POS = 0
I think what you're looking for is the LOCATE_IN_STRING() scalar function. This is what Info Center has to say if you use a negative start value:
If the value of the integer is less than zero, the search begins at
LENGTH(source-string) + start + 1 and continues for each position to
the beginning of the string.
Combine that with the LENGTH() and RIGHT() scalar functions, and you can get what you want:
SELECT
RIGHT(
FILEPATH
,LENGTH(FILEPATH) - LOCATE_IN_STRING(FILEPATH,'/',-1)
)
FROM FOO
One way to do this is by taking advantage of the power of DB2s XQuery engine. The following worked for me (and fast):
SELECT DISTINCT XMLCAST(
XMLQuery('tokenize($P, ''/'')[last()]' PASSING FILEPATH AS "P")
AS VARCHAR(512) )
FROM FOO
Here I use tokenize to split the file path into a sequence of tokens and then select the last of these tokens. The rest is only conversion from SQL to XML types and back again.
I know that the problem from the OP was already solved but I decided to post the following anyway to hopefully help others like me that land here.
I came across this thread while searching for a solution to my similar problem which had the exact same requirement but was for a different kind of database that was also lacking the REVERSE function.
In my case this was for a OpenEdge (Progress) database, which has a slightly different syntax. This made the INSTR function available to me that most Oracle typed databases offer.
So I came up with the following code:
SELECT
SUBSTRING(
foo.filepath,
INSTR(foo.filepath, '/',1, LENGTH(foo.filepath) - LENGTH( REPLACE( foo.filepath, '/', '')))+1,
LENGTH(foo.filepath))
FROM foo
However, for my specific situation (being the OpenEdge (Progress) database) this did not result into the desired behaviour because replacing the character with an empty char gave the same length as the original string. This doesn't make much sense to me but I was able to bypass the problem with the code below:
SELECT
SUBSTRING(
foo.filepath,
INSTR(foo.filepath, '/',1, LENGTH( REPLACE( foo.filepath, '/', 'XX')) - LENGTH(foo.filepath))+1,
LENGTH(foo.filepath))
FROM foo
Now I understand that this code won't solve the problem for T-SQL because there is no alternative to the INSTR function that offers the Occurence property.
Just to be thorough I'll add the code needed to create this scalar function so it can be used the same way like I did in the above examples.
-- Drop the function if it already exists
IF OBJECT_ID('INSTR', 'FN') IS NOT NULL
DROP FUNCTION INSTR
GO
-- User-defined function to implement Oracle INSTR in SQL Server
CREATE FUNCTION INSTR (#str VARCHAR(8000), #substr VARCHAR(255), #start INT, #occurrence INT)
RETURNS INT
AS
BEGIN
DECLARE #found INT = #occurrence,
#pos INT = #start;
WHILE 1=1
BEGIN
-- Find the next occurrence
SET #pos = CHARINDEX(#substr, #str, #pos);
-- Nothing found
IF #pos IS NULL OR #pos = 0
RETURN #pos;
-- The required occurrence found
IF #found = 1
BREAK;
-- Prepare to find another one occurrence
SET #found = #found - 1;
SET #pos = #pos + 1;
END
RETURN #pos;
END
GO
To avoid the obvious, when the REVERSE function is available you do not need to create this scalar function and you can just get the required result like this:
SELECT
SUBSTRING(
foo.filepath,
LEN(foo.filepath) - CHARINDEX('\', REVERSE(foo.filepath))+2,
LEN(foo.filepath))
FROM foo
You could just do it in a single statement:
select distinct reverse(substring(reverse(FILEPATH), 1, charindex('/', reverse(FILEPATH))-1))
from filetable

A SQL Problem. Check condition with in a comma seperated value

I have a vairable
DECLARE #AssignOn nvarchar(20)='0,2,5'
I want to check a condition like this
DECLARE #index int
SET DATEFIRST 7
SELECT #index=DATEPART(DW, GETDATE())-1
IF(CONVERT(nvarchar(2),#index) IN #AssignOn)
IN cannot be used here . Any other methods to do this INLINE
You can use CharIndex to find if you have a match. It returns a non zero value if the first string appears in the second.
IF(CHARINDEX(CONVERT(nvarchar(2),#index), #AssignOn) > 0)
The easiest way to do this is to search for the substring ',needle,' in the csv list string. However, this doesn't work correctly for the first and last elements. This can be overcome by concatenating a comma onto each side of the csv list string.
An example in SQL might be:
SELECT
CHARINDEX(','+ NEEDLE +',', ','+ HAYSTACK +',')
FROM table;
Or using LIKE:
SELECT *
FROM table
WHERE ','+ HAYSTACK +',' LIKE '%,'+ NEEDLE +',';
IF CHARINDEX(','+CONVERT(nvarchar(2),#index)+',', ','+#AssignOn+',') <> 0
As you actually define the values in the code you could instead;
DECLARE #AssignOn TABLE (value int)
INSERT #AssignOn VALUES (0),(2),(5)
... #index IN (SELECT value FROM #AssignOn)