一列的SQL Server唯一联合

您不需要工会。只需离开工作室即可加入项目，然后使用合并

以下

WITH g_studio_UsersInRole AS  --Sampledata(    SELECt 1  userId        ,1       roleId   , 'TRUE' value    UNIOn SELECT 1,       2,       'TRUE'    UNIOn SELECT 1,       3,       'TRUE'    UNIOn SELECT 2,       1,       'FALSE'), g_project_UsersInRole as --Sampledata(    SELECT 1 userId  ,       2  roleId  ,     'FALSE'  value ,     1 projectId    UNIOn SELECT 2,       1,       'TRUE',     1)SELECT     sRole.userId,    sRole.roleId,    COALESCE(pRole.Value,sRole.value)  as valueFROM     g_studio_UsersInRole sRole    LEFT JOIN g_project_UsersInRole  pRole    ON sRole.userId = pRole.userId      and sRole.roleId = pRole.roleId     and pRole.ProjectId = 1

返回以下结果

userId      roleId      value----------- ----------- -----11TRUE12FALSE13TRUE21TRUE