Query Multi-Select Picklist in Apex with Visual Force Page

Question

I'm having some difficulty figuring out the correct way to do this. If I have a visual force page with a multi-select picklist and I need to run the selected values through a query. The issue is I do not have those values until they select them. For instance, let's say I have John, Dan, and Nancy as the values I know the query would be:

Select FirstName From Contact Where FirstName Includes ('John;Dan;Nancy')

I know there is a limitation with INCLUDES so this wouldn't work.

String s = 'John;Dan;Nancy';
Select FirstName From Contact Where FirstName Includes (:s)

But what if I need to store those values in a variable in the Visual force page. Let's say the user selected John and Dan. I can store those values in a String or String array, but how would you reference those in query? Can you store the multi-select value in string and referenc it a query using the includes statement or would you need to join string in Dynamic SOQL. I'm also wary on SQL Injection, so I'm looking for the best method.

Thanks,

Andy

Answer 1

Your query is looking for an exact match. ie where the FirstName includes John, Dan and Nancy. If you wanted to search for records that have one or more of those values set then try this:

Select FirstName From Contact Where FirstName Includes ('John', 'Dan', 'Nancy')

You could also use a List, as shown here:

List<String> s = new List<String>{'John', 'Dan', 'Nancy'};
Select FirstName From Contact Where FirstName Includes (:s)

See here for more information