comparing input parameter with xml value using like in sql - sql

I have an SQL table with a column which stores xml like this
<AdditionalInfo><RegistrantID>16279</RegistrantID></AdditionalInfo>
I have created a stored procedure like this:
CREATE PROC hr_GetJobStatusByRegistrantId
#registrantId VARCHAR
AS
BEGIN
SELECT TOP 1
[IsSubscribed]
FROM [Hrge].[dbo].[hr_Jobs]
where AdditionalInfo LIKE '%<AdditionalInfo><RegistrantID>%' + #registrantId + '%</RegistrantID></AdditionalInfo>%'
END
When I run this stored procedure, I get null:
exec hr_GetJobStatusByRegistrantId '16279'
If I make this parameter integer then I get convertion to int error.
Please suggest me solution to this.

(Just expanding the comment into an answer)
You should always specify the width of a char or a varchar field, because unless you do the default kicks in. The documentation says:
When n is not specified in a data definition or variable declaration
statement, the default length is 1. When n is not specified when using
the CAST and CONVERT functions, the default length is 30.
which means that in your case you have actually defined #registrantId as VARCHAR(1) so the value of '16279' was trimmed to a single character ('1') and you actually searched for
%<AdditionalInfo><RegistrantID>%1%</RegistrantID></AdditionalInfo>%
in the database. This actually returned the IsSubscribed flag for the first record it found in the DB that had a '1' anywhere in the RegistrantID field. You got lucky that the value was something wrong, so you noticed it.
Additionally you are using % around your parameter. This means that when you search for a RegistrantID of 123, you'll get results for 123, 1234, 2123, 51236, etc, etc, and then just take the first one, whichever that one is (decided by the database, since there is no order clause). It's my guess that you need an exact match, so you should remove those, and just use
'%<AdditionalInfo><RegistrantID>' + #registrantId
+ '</RegistrantID></AdditionalInfo>%'
Also, it the RegistrantId is actually a number, it would be nice if the interface of the procedure reflected that, so it could be defined with
#registrantId int
and then converted to a string in the query
'%<AdditionalInfo><RegistrantID>' + cast(#registrantId as varchar(10))
+ '</RegistrantID></AdditionalInfo>%'

Related

Getting different results from LIKE query and stored procedure for (starts and ends with) search

I am trying to implement a stored procedure that gets the two parameters #startsWith and #endsWith and constructs this query string:
#startswith + '%' + #endsWith
To search for entries of a single column (Name) that start end end with the parameters. Here is the stored procedure:
CREATE PROCEDURE termNameStartsEndsWith(
#startsWith AS nvarchar,
#endsWith AS nvarchar
)
AS
BEGIN
SELECT * FROM Term WHERE
Name LIKE (#startsWith + '%' + #endsWith)
END;
However, I get unexpected results when one of the two query parameters is empty (''). Here is an example where I would expect only results where the Term column entry starts with 'water', but i get a bunch of additional rows:
I dont get these results when executing as a query:
So I expect that the problem is coming from the empty string concatenation being handled differently in a stored procedure? If so, how can I adapt the procedure accordingly?
Thanks for the help in advance.
As noted by Larnu in the comments, the issue isn't the query, it's your parameter declarations.
You have two NVARCHAR(n) parameters declared, but there is no length declared for either of them. From the documentation (emphasis added):
When n is not specified in a data definition or variable declaration statement, the default length is 1. When n is not specified with the CAST function, the default length is 30.
So both parameters are exactly one character long. Conveniently, SQL Server will let you assign a longer value to that parameter, and then just take the first character and silently truncate the rest.
Modify your parameters to have length definitions, and you should be in business.

Trigger to convert empty string to 'null' before it posts in SQL Server decimal column

I've got a front table that essentially matches our SSMS database table t_myTable. Some columns I'm having problems with are those with numeric data types in the db. They are set to allow null, but from the front end when the user deletes the numeric value and tries to send a blank value, it's not posting to the database. I suspect because this value is sent back as an empty string "" which does not translate to the null allowable data type.
Is there a trigger I can create to convert these empty strings into null on insert and update to the database? Or, perhaps a trigger would already happen too late in the process and I need to handle this on the front end or API portion instead?
We'll call my table t_myTable and the column myNumericColumn.
I could also be wrong and perhaps this 'empty string' issue is not the source of my problem. But I suspect that it is.
As #DaleBurrell noted, the proper place to handle data validation is in the application layer. You can wrap each of the potentially problematic values in a NULLIF function, which will convert the value to a NULL if an empty string is passed to it.
The syntax would be along these lines:
SELECT
...
,NULLIF(ColumnName, '') AS ColumnName
select nullif(Column1, '') from tablename
SQL Server doesn't allow to convert an empty string to the numeric data type. Hence the trigger is useless in this case, even INSTEAD OF one: SQL Server will check the conversion before inserting.
SELECT CAST('' AS numeric(18,2)) -- Error converting data type varchar to numeric
CREATE TABLE tab1 (col1 numeric(18,2) NULL);
INSERT INTO tab1 (col1) VALUES(''); -- Error converting data type varchar to numeric
As you didn't mention this error, the client should pass something other than ''. The problem can be found with SQL Profiler: you need to run it and see what exact SQL statement is executing to insert data into the table.

FnSplit not working for SQL stored procedure to take multiple parameters

I have a stored procedure that currently takes in one value(ChainId) for a parameter. I am trying to allow the user to select multiple values of(ChainId). My where statement is below. Could someone help point me in a better direction than I am going now. Currently the query will run and return no data if I select multiple values for the parameter.
WHERE EndAuth is null AND CL.CHIND in(
SELECT [Value] FROM dbo.FnSplit(#ChainId, ','))
ORDER BY CL.CHIND
This is a popular function in SQL Server, so I'll assume you're working with that. Make sure your parameter is of type Varchar(MAX). #ChainId is passed as your string (ideally for SSRS) and ',' is passed as your delimiter. In SSRS, if you have a text box for your users to manually enter multiple values, they will enter something like 'value1, value2, value3'.
Test this out:
Declare #Yes_No Varchar(Max)
Set #Yes_No = 'y,n'
Select #yes_no
Select * from SplitString('y,n',',')
Select * from SplitString(#Yes_No,',')
Your results will be
y,n
----
y
n
----
y
n
Why I say to use Varchar(Max) and not int, or Varchar(10) for example, is because that would stop the function from reading all the values prematurely.
Try this:
Declare #Yes_No Varchar(1)
Set #Yes_No = 'y,n'
Select * from SplitString(#Yes_No,',')
The result will be:
y
The reason is because the function only accepts a value of 1 character in length, and splits that. As you can see, there isn't much to split.
This is just the way SSRS accepts parameters. FN_Split isn't necessarily a built-in function, but a widely popular one designed to allow you to pass multiple values to a string, with a pre-specified delimiter. So make sure you also go to your parameter in the report and specify that it will allow for multiple values. You will also want to supply a list of potential values for your users to select from. You'll either do this by manually populating a small list or providing another data source in the form of a stored procedure or table.

How do you pass values for a parameter by position when you need to check multiple values?

I created a stored procedure (spBalanceRange) with 2 optional parameters. They've been set to a default value and the sp works fine when I pass only 1 value per parameter by position. However, I have a situation where I'm trying to pass, by position, two strings immediately followed by a wildcard. I want the user to be able to search for Vendor names that start with either 'C%' or 'F%'. Here's the gist of the CREATE PROC statement:
CREATE PROC spBalanceRange
#VendorVar varchar(40) = '%',
#BalanceMin money = 1.0
...
Here's what I've tried so far, but doesn't work:
EXEC spBalanceRange '(C%|F%)', 200.00;
EXEC spBalanceRange 'C%|F%', 200.00;
Is there a way to check for 2 or more string values with a wildcard when passed by position? Thanks.
EDIT: According to your comments you are looking for the first letter of a vendor's name only.
In this special case I could suggest an easy, not well performing but really simple approach. CHARINDEX returns a number greater than zero, if a character appears within a string. So you just have to pass in all your lookup-first-characters as a simple "chain":
DECLARE #DummyVendors TABLE(VendorName VARCHAR(100));
INSERT INTO #DummyVendors VALUES
('Camel Industries')
,('Fritz and Fox')
,('some other');
DECLARE #ListOfFirstLetters VARCHAR(100)='CF';
SELECT VendorName
FROM #DummyVendors AS dv
WHERE CHARINDEX(LEFT(dv.VendorName,1),#ListOfFirstLetters)>0
This was the former answer
Checking against more than one value needs either a dedicated list of compares
WHERE val=#prm1 OR val=#prm2 OR ... (you know the count before)
...or you use the IN-clause
WHERE LEFT(VenoderName,1) IN ('C','F', ...)
...but you cannot pass the IN-list with a parameter like ... IN(#allValues)
You might think about a created TYPE to pass in all your values like a table and use an INNER JOIN as filter: https://stackoverflow.com/a/337864/5089204 (and a lot of other examples there...)
Or you might think of dynamic SQL: https://stackoverflow.com/a/5192765/5089204
And last but not least you might think of one of the many split string approaches. This is one of my own answers, section "dynamic IN-statement": https://stackoverflow.com/a/33658220/5089204
I'm answering my own question, and maybe other solutions exist but here is what had to happen with my stored procedure in order to pass variables by position:
CREATE PROC spBalanceRange
#VendorVar varchar(40) = '%',
#BalanceMin money = 1.0
AS
IF (#VendorVar = '%' AND #BalanceMin IS NULL OR #BalanceMin = '')
BEGIN
PRINT 'BalanceMin cannot be null.';
END
IF (#VendorVar = % AND #BalanceMin IS NOT NULL)
BEGIN
(sql statement using parameters)
END
EXEC spBalanceRange '[C,F]%', 200.00;
That's what I know.

Convert Binary Id Field to Text

I need the text (representation) of a id field in SQL Server 2005. Is there a way, we can generate the textual representation of the id field?
For instance, if the id field reads as 0x00000000000002F0, I need the text value of 0x00000000000002F0 so that I can run SUBSTR operations on the same.
Constraints
I am not allowed to create a stored procedure in the Database (as creation of SP is not allowed)
Thanks!
You can convert unicode strings to binary using
SELECT CONVERT(VARBINARY(40),N'Hello World')
(returns 0x480065006C006C006F00200057006F0072006C006400)
Convert from binary back to unicode using
SELECT CONVERT(NVARCHAR(20), 0x480065006C006C006F00200057006F0072006C006400)
(returns 'Hello World')
Whilst it's not immediately obvious to me why you would want to do this for comparison purposes (as opposed to matching binary values), the undocumented function sys.fn_varbintohexstr should do the trick
declare #vb binary(8)
,#vc varchar(20)
set #vb = 0x00000000000002F0
set #vc = sys.fn_varbintohexstr(#vb)
--prove that this works by concatenating a string to the varchar value
select #vb, '#' + #vc