使用相关子查询
UPDATe eSET ADMITTED = (SELECT max(IAR_ServiceDate) FROM ansicache..x_refClaim_table x WHERe e.ENCOUNTER = x.PatAcctNumber)FROM ansicache..ENCOUNTERS e

使用相关子查询
UPDATe eSET ADMITTED = (SELECT max(IAR_ServiceDate) FROM ansicache..x_refClaim_table x WHERe e.ENCOUNTER = x.PatAcctNumber)FROM ansicache..ENCOUNTERS e