dapper “IN” clause not working with multiple values

问题

Scenario:

I have a string property in my model that holds the IDs from a MultiSelectList @Html.ListBox. If I select two list items, my property value will look like this 0100,0500.

The problem:

Dapper where clause will only work with a single value:

CODE IN (@SomeCode) // for example, 0100 or 0500 returns results
CODE IN (@SomeCode) // 0100,0500 does not return results.

回答1:

That's because you don't need to tell Dapper to use parenthesis (). It will do fine by its own. Try this:

var codes = new List<string> { "0100","0500"};
var sql = "select * from SomeTable where CODE IN @codes";
var items = connection.Query(sql, new { codes });

来源：https://stackoverflow.com/questions/31997381/dapper-in-clause-not-working-with-multiple-values