具有连接条件的LINQ更新查询

尝试使用join with on condition和condition执行LINQ更新查询

遵循我的SQL查询

UPDATE tbl_gs_related_orders  
SET RelatedCOI = sop.ServiceOrderNo  
FROM tbl_service_order_progress sop   
JOIN tbl_gs_related_orders ro  ON sop.parentid = ro.RelatedOrderParentId  
AND ro.RelatedCOIIdentifier collate database_default = sop.InstanceIdentifier collate database_default 
WHERE ro.ParentId = @PARENTID  
AND ro.relatedorderparentid IS NOT NULL

我想将此查询转换为LINQ，因此在更新LINQ查询之后，出现了一些错误，如“join子句中某个表达式的类型不正确，调用join时类型推断失败”

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为equals子句创建匿名类型时使用相同的别名：

from c in ctxParser.TBL_SERVICE_ORDER_PROGRESS
join o in ctxParser.tbl_GS_Related_Orders on new { ParentId = c.ParentId, InstanceIdentifier = c.InstanceIdentifier }
equals new { ParentId = o.RelatedOrderParentId, InstanceIdentifier = o.RelatedCOIIdentifier }

from c in ctxParser.TBL_SERVICE_ORDER_PROGRESS
join o in ctxParser.tbl_GS_Related_Orders on new { ParentId = c.ParentId, InstanceIdentifier = c.InstanceIdentifier }
equals new { ParentId = o.RelatedOrderParentId, InstanceIdentifier = o.RelatedCOIIdentifier }