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[QinYinXin]

供应者 SUPPLIER（SNO，SNAME，CITY） SNO供应者编号，SNAME为供应者姓名，CITY所在城市
零件 PART（PNO，PNAME，WEIGHT）PNO零件号，PNAME零件名称，WEIGHT重量
工程 JOB（JNO，JNAME，CITY） JNO工程号，JNAME工程名，CITY所在城市
联系关系 SPJ（SNO，PNO，JNO，QTY） QTY为数量


查找给工程J1提供零件P1的供应者号SNO

[dawugui]

[Quote=引用楼主 qinyinxin 的回复:]
供应者 SUPPLIER（SNO，SNAME，CITY）  SNO供应者编号，SNAME为供应者姓名，CITY所在城市
      零件  PART（PNO，PNAME，WEIGHT）PNO零件号，PNAME零件名称，WEIGHT重量
      工程  JOB（JNO，JNAME，CITY） JNO工程号，JNAME工程名，CITY所在城市
      联系关系 SPJ（SNO，PNO，JNO，QTY） QTY为数量


    查找给工程J1提供零件P1的供应者号SNO
[/Quote]

select t1.sno 
from SUPPLIER t1 , PART t2 , JOB = t3 , SPJ t4
where t1.sno = t4.sno and t4.jno = t3.jno and t4.pno = t2.pno and t3.JNO = 'J1' and t2.PNO = 'P1'

[icelovey]

SELECT
FROM JOB T1 INNER JOIN SPJ T2 ON J1.JNO = T2.JNO
	    INNER JOIN PART T3 ON T2.PNO = T3.PNO
	    INNER JOIN SUPPLIER T4 ON T4.SNO = T2.SNO
WHERE T1.JNO = 'J1' AND T3.PNO = 'P1'

[icelovey]

没写返回列 ， 这样
SELECT t1.SNO
FROM JOB T1 INNER JOIN SPJ T2 ON J1.JNO = T2.JNO
	    INNER JOIN PART T3 ON T2.PNO = T3.PNO
	    INNER JOIN SUPPLIER T4 ON T4.SNO = T2.SNO
WHERE T1.JNO = 'J1' AND T3.PNO = 'P1'

[icelovey]

这破键盘

SELECT t4.SNO
FROM JOB T1 INNER JOIN SPJ T2 ON J1.JNO = T2.JNO
	    INNER JOIN PART T3 ON T2.PNO = T3.PNO
	    INNER JOIN SUPPLIER T4 ON T4.SNO = T2.SNO
WHERE T1.JNO = 'J1' AND T3.PNO = 'P1'

[dawugui]

第一个表可以不用

select t4.sno 
from PART t2 , JOB = t3 , SPJ t4
where t4.jno = t3.jno and t4.pno = t2.pno and t3.JNO = 'J1' and t2.PNO = 'P1'

[QinYinXin]

谢谢了

[icelovey]

[Quote=引用 5 楼 dawugui 的回复:]
第一个表可以不用

SQL codeselect t4.snofrom PART t2 , JOB= t3 , SPJ t4where t4.jno= t3.jnoand t4.pno= t2.pnoand t3.JNO='J1'and t2.PNO='P1'
[/Quote]
其实你如果单单是查个SNO的话， 只要2个表就可以了

SELECT t2.SNO
FROM JOB T1 INNER JOIN SPJ T2 ON J1.JNO = T2.JNO
WHERE T1.JNO = 'J1' AND T2.PNO = 'P1'