SQL联合查询语言

SQL 联合查询

SELECT patient.uid, patient.`patientid`,course.`coursename`, site.`name` FROM tmspatient patient, tmscourse course , tmssite site WHERE patient.`uid` = course.patientuid AND course.`uid` = site.`courseuid`

ef查询

var queryDgSessions = (from dgs in _dbWrapper._RT_TMSEntities.tmsdeliverybeamgroup_session
                                    join dg in _dbWrapper._RT_TMSEntities.tmsdeliverybeamgroups on dgs.deliverybeamgroupuid equals dg.uid 
                                    join t in _dbWrapper._RT_TMSEntities.tmstreatmentsessions on dgs.treatmentsessionuid equals t.uid
                                    select new
                                    {
                                        BeamGroupUid = dg.uid,
                                        TreatmentsessionUid =dgs.treatmentsessionuid,
                                        TreatmentSession = new DM_Cal_Session{
                                        UID = t.uid,
                                        IsScheduled = t.isscheduled,
                                        StartDate = t.plandate,
                                        StepUid =t.stepuid,
                                        TimeStamp = t.updatetime,
                                      },
                                   } );

select where in用法

SELECT * FROM student WHERE uid IN (
    SELECT studentuid FROM course WHERE uid IN (
        SELECT courseuid FROM teacher WHERE uid IN('11111111')))