最近用Entity Framework 开发的时候，发现一个问题，在默认情况下，EF不能对一个没有主键的表进行更新、插入和删除的动作。

那么，应该怎么处理没有主键的表呢？

我们打开这个表的edmx文件，可以看到以下的xml片段

                 
      
       SELECT       "REP"."ZONE" AS "ZONE",       "REP"."NO" AS "NO",       "REP"."HELP_NO" AS "HELP_NO",       "REP"."NO_TYPE" AS "NO_TYPE",       "REP"."ID_NO" AS "ID_NO",       "REP"."NAME" AS "NAME",       "REP"."TEL" AS "TEL",       "REP"."MAIL_NO" AS "MAIL_NO",       "REP"."ADDRESS1" AS "ADDRESS1",       "REP"."ADDRESS2" AS "ADDRESS2",       "REP"."JOINDATE" AS "JOINDATE",       "REP"."ELITE_D" AS "ELITE_D",       "REP"."PD1" AS "PD1",       "REP"."CUR_CPS" AS "CUR_CPS",       "REP"."PREV_CPS1" AS "PREV_CPS1",       "REP"."YEAR_CPS" AS "YEAR_CPS",       "REP"."IA_CPS" AS "IA_CPS",       "REP"."PREV_BAL" AS "PREV_BAL",       "REP"."CUR_BAL" AS "CUR_BAL",       "REP"."ELITE" AS "ELITE",       "REP"."CUR_CAMP" AS "CUR_CAMP",       "REP"."SALES" AS "SALES",       "REP"."RETURN" AS "RETURN",       "REP"."NO_ACT" AS "NO_ACT",       "REP"."PD_NO" AS "PD_NO",       "REP"."CUR_ORDER" AS "CUR_ORDER",       "REP"."BIRTHDAY" AS "BIRTHDAY",       "REP"."RNAM" AS "RNAM",       "REP"."POST_YN" AS "POST_YN",       "REP"."CARD_NO" AS "CARD_NO",       "REP"."CARD_YYYYMM" AS "CARD_YYYYMM",       "REP"."TEL2" AS "TEL2",       "REP"."MOBILE" AS "MOBILE",       "REP"."EMAIL" AS "EMAIL",       "REP"."PREV_CPS2" AS "PREV_CPS2",       "REP"."SEMAIL" AS "SEMAIL",       "REP"."PASSWORD" AS "PASSWORD",       "REP"."NEXT_CPS" AS "NEXT_CPS",       "REP"."TRAN_D" AS "TRAN_D",       "REP"."PASS_CNT" AS "PASS_CNT",       "REP"."ORDER_CT" AS "ORDER_CT",       "REP"."ORDER_AT" AS "ORDER_AT",       "REP"."SNAME" AS "SNAME",       "REP"."NOTES1" AS "NOTES1",       "REP"."NOTES2" AS "NOTES2",       "REP"."PPWD" AS "PPWD",       "REP"."SALES6" AS "SALES6",       "REP"."NO5" AS "NO5",       "REP"."SALES4" AS "SALES4",       "REP"."DELIVER" AS "DELIVER",       "REP"."ISWHWB" AS "ISWHWB",       "REP"."LOS" AS "LOS",       "REP"."CREDITLINE" AS "CREDITLINE",       "REP"."OCCUPATION" AS "OCCUPATION",       "REP"."ENTRYLOCATION" AS "ENTRYLOCATION",       "REP"."SOURCE" AS "SOURCE",       "REP"."SURVEYTAG" AS "SURVEYTAG",       "REP"."HMDATE" AS "HMDATE",       "REP"."ISRCVSMS" AS "ISRCVSMS",       "REP"."PAYMETHOD" AS "PAYMETHOD",       "REP"."ISPBAMCOURSE" AS "ISPBAMCOURSE",       "REP"."ISBSDCOURSE" AS "ISBSDCOURSE",       "REP"."BSADATE" AS "BSADATE",       "REP"."CUR_NETSALES" AS "CUR_NETSALES",       "REP"."WEBPCDATE" AS "WEBPCDATE",       "REP"."WEBPC" AS "WEBPC",       "REP"."ISMCNOTICE" AS "ISMCNOTICE",       "REP"."OLDNO" AS "OLDNO",       "REP"."EMAILACCOUNT" AS "EMAILACCOUNT",       "REP"."MCDATE" AS "MCDATE",       "REP"."PASS_CRTDATE" AS "PASS_CRTDATE",       "REP"."STARXNO" AS "STARXNO",       "REP"."ZONEID" AS "ZONEID",       "REP"."ORDER_INFO" AS "ORDER_INFO",       "REP"."TRAN_D_EC_DATE" AS "TRAN_D_EC_DATE",       "REP"."REALTITLEID" AS "REALTITLEID",       "REP"."PAIDTITLEID" AS "PAIDTITLEID",       "REP"."PUBLICTITLEID" AS "PUBLICTITLEID",       "REP"."ISASLF" AS "ISASLF",       "REP"."ASLFROSTARTCAMP" AS "ASLFROSTARTCAMP",       "REP"."ASLFROENDCAMP" AS "ASLFROENDCAMP",       "REP"."ISVIRTUALID" AS "ISVIRTUALID",       "REP"."ASLFSPONSORID" AS "ASLFSPONSORID",       "REP"."MPCACTCPS" AS "MPCACTCPS",       "REP"."MPCORDVAL" AS "MPCORDVAL",       "REP"."ASLFCDBENDCAMP" AS "ASLFCDBENDCAMP",       "REP"."ASLFSTARTCAMP" AS "ASLFSTARTCAMP",       "REP"."ISDRCERT" AS "ISDRCERT",       "REP"."DRCERTSTARTCAMP" AS "DRCERTSTARTCAMP",       "REP"."DRCERTENDCAMP" AS "DRCERTENDCAMP",       "REP"."DRFOUSECAMP" AS "DRFOUSECAMP",       "REP"."MAIL_NO1" AS "MAIL_NO1",       "REP"."ADDRESS12" AS "ADDRESS12",       "REP"."ADDRESS22" AS "ADDRESS22",       "REP"."RECOMMENDERID" AS "RECOMMENDERID",       "REP"."RECOMMENDERNAME" AS "RECOMMENDERNAME",       "REP"."RECOMMENDERNATIONALID" AS "RECOMMENDERNATIONALID",       "REP"."COAPPLICANTNAME" AS "COAPPLICANTNAME",       "REP"."COMPANYNAME" AS "COMPANYNAME",       "REP"."ISEINVOICE" AS "ISEINVOICE",       "REP"."ISDONATE_INVOICE" AS "ISDONATE_INVOICE",       "REP"."DRM_CREATEDDATE" AS "DRM_CREATEDDATE"      FROM "FOREST"."REP" "REP"
                
     

 

我再加入一个有主键的表进行对比，可以看到有主键的表的定义如下。

我们把没有主键的<EntitySet>照着上面这个节点进行更改：删除<DefiningQuery>节点，将store:Schema=”FOREST”更改为Schema=”FOREST”。这样我们就可以对之前没有设置主键的表进行更新、删除以及插入操作了。

无主键的表SSDL定义其实更像是视图，我有一点不明的是store:这个命名空间的作用是什么，为什么只是删除<DefiningQuery>不行，还需要将Schema属性的store命名空间删除才可以。以上都是我还不明白的地方，只是作为一个解决方案，它确实简单可行。