How to pass parameter value to SQL IN clause in query resource of custom component?

Example :

<tr>

<td>QroleDisplayNamesList</td>

<td>SELECT DISTINCT dRoleName, dRoleDisplayName FROM RoleDefinition WHERE dRoleName IN (?)</td>

<td>roleList varchar</td>

</tr>

what should be the format of roleList in this case? is it just a comma seperated values with no '' like role1,role2,role3 or should it be 'role1','role2','role3'?