sql - Join 中的用例语句

Question

大家好，我想在使用此查询的连接中使用 case 语句，但出现错误

Select CONVERT(VARCHAR(10), SII.SIDATE,103)DATE,SII.SALEID,SII.ItemName,SI.TenancyID

FROM F_SALESINVOICEITEM SII
INNER JOIN F_SALESINVOICE SI ON  SI.SALEID=SII.SALEID 
INNER JOIN #TempTableSearch ts ON CASE
 WHEN ts.ACCOUNTTYPE = '1' THEN ts.ACCOUNTID=SI.TENANCYID
  WHEN ts.ACCOUNTTYPE='2' THEN ts.ACCOUNTID=SI.EMPLOYEEID
   WHEN ts.ACCOUNTTYPE='3' THEN ts.ACCOUNTID=SI.SUPPLIERID
    WHEN ts.ACCOUNTTYPE='4' THEN ts.ACCOUNTID=SI.SALESCUSTOMERID

错误

Incorrect syntax near '='.

请帮我解决这个错误。

Answer 1

应该是，

ON 
ts.ACCOUNTID =  CASE
                    WHEN ts.ACCOUNTTYPE = '1' THEN SI.TENANCYID
                    WHEN ts.ACCOUNTTYPE = '2' THEN SI.EMPLOYEEID
                    WHEN ts.ACCOUNTTYPE = '3' THEN SI.SUPPLIERID
                    WHEN ts.ACCOUNTTYPE = '4' THEN SI.SALESCUSTOMERID
                END