comparing a column to a list of values in t-sql

Question

I have a situation where I am displaying records on a page, and I need a way for the user to select a subset of those records to be displayed on another page. These records

Answer 1

You can use the solution Joel Spolsky recently gave for this problem.

SELECT * FROM MyTable
WHERE ',' + 'comma,separated,list,of,words' + ','
  LIKE '%,' + MyTable.word + ',%';

That solution is clever but slow. The better solution is to split the comma-separated string, and construct a dynamic SQL query with the IN() predicate, adding a query parameter placeholder for each element in your list of values:

SELECT * FROM MyTable
WHERE word IN ( ?, ?, ?, ?, ?, ?, ?, ? );

The number of placeholders is what you have to determine when you split your comma-separated string. Then pass one value from that list per parameter.

If you have too many values in the list and making a long IN() predicate is unwieldy, then insert the values to a temporary table, and JOIN against your main table:

CREATE TEMPORARY TABLE TempTableForSplitValues (word VARCHAR(20));

...split your comma-separated list and INSERT each value to a separate row...

SELECT * FROM MyTable JOIN TempTableForSplitValues USING (word);

Also see many other similar questions on SO, including:

• Dynamic SQL Comma Delimited Value Query
• Passing a varchar full of comma delimited values to a SQL Server IN function
• Parameterized Queries with Like and In
• Parameterizing a SQL IN clause?