Question

I have a query like:

SELECT ...
FROM ...
WHERE .. AND SomeID = @someID

I’m inheriting this massive stored procedure that has some dynamic elements to it, so I need to get the value of someID from a column in another table i.e. perform a lookup.

How can I do that?

The other column looks like:

TypeValue
'SomeID=1232,OtherID=3383'

Some the column TypeValue is VARCHAR(1000), and it contains a comma seperated string of type & value pairs.

So I need to split on the , and then split on the = so somehow get:

SET @SomeID = SELECT TypeValue FROM MyTABLE WHERE ..

How can I do this?

(note, this is sql server 2000)

Answer 1

Assuming you’re stuck with bad design, this doesn’t require dynamic SQL:

USE tempdb;
GO

CREATE TABLE dbo.foo(ID INT, TypeValue VARCHAR(1000));

INSERT dbo.foo SELECT 1, 'SomeID=1232,OtherID=3383';
INSERT dbo.foo SELECT 2, 'Blat=prong,SomeID=1254';
INSERT dbo.foo SELECT 3, 'Foo=bar,x=23';
INSERT dbo.foo SELECT 4, 'SomeID=767';
INSERT dbo.foo SELECT 5, 'x=y,SomeID=126,OtherID=3383';

SELECT ID, Value = SUBSTRING(TypeValue, 
  CHARINDEX('SomeID', TypeValue) + 7, 
  COALESCE(NULLIF(CHARINDEX(',', SUBSTRING(TypeValue, 
    CHARINDEX('SomeID', TypeValue) + 8, 1000)), 0), 1000))
FROM dbo.foo
WHERE ',' + TypeValue LIKE '%,SomeID=%';

Results:

ID  Value
--- -----
1   1232
2   1254
4   767
5   126

If you know which row you want:

DECLARE @ID INT, @Param VARCHAR(32);
SET @ID = 5;
SET @Param = 'SomeID';


DECLARE @val INT;

SELECT @val = SUBSTRING(TypeValue, 
  CHARINDEX(@Param, TypeValue) + LEN(@Param) + 1, 
  COALESCE(NULLIF(CHARINDEX(',', SUBSTRING(TypeValue, 
    CHARINDEX(@Param, TypeValue) + LEN(@Param) + 2, 1000)), 0), 1000))
FROM dbo.foo
WHERE ID = @ID 
AND ',' + TypeValue LIKE '%,' + @Param + '=%';

PRINT @val;

Result:

126

This doesn’t guard against someone putting a string into the SomeID value, of course, so may be safer to only convert to an INT if it is proven to be numeric. But you get the point.