Dynamic SQL rows to column

Question

I have a table something like
                              WHERE    IN
                              Age           18
                              Year           2012,2013
                              Color         Blue
--etc
                              I would like to create a dynamic statement base on this table
                              Dyanmic SQL:
                              WHERE AGE IN (18) and Year IN (2012,2013) and Color IN (‘Blue’)
I am using SQL server 2008 R2. How can I do this using XML path or something

Answer 1

Here you go:
DECLARE @tbl TABLE ([WHERE]   sysname NOT NULL,
                     [IN]     nvarchar(200))
INSERT @tbl([WHERE], [IN])
   VALUES ('Age', '18'), ('Year', '2012,2013'), ('Colour', 'Blue,Yellow')
DECLARE @where nvarchar(MAX)
SELECT @where =
   (SELECT [WHERE] + ' IN (' +
            CASE WHEN [IN] LIKE '%[^0-9,]%'
                 THEN replace(quotename([IN], ''''), ',', ''',''')
                 ELSE [IN]
            END + ') AND '
    FROM   @tbl
    FOR XML PATH(''), TYPE).value('.', 'nvarchar(MAX)') + ' 1 = 1'
SELECT @where
However, this is somewhat brittle. I'm assuming that a comma is a list separator; never part of a value searched for. I'm also assume that as long as a value is digits only, it is numeric, else it is a string. This would fail if there is a date value
on the form YYYYMMDD.
Probably you should store metadata somwhere, so that you know the data type of a column.
Erland Sommarskog, SQL Server MVP, [email protected]