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Homework/Homework250320/Query.sql

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+USE Homework250320;
+Go
+-- 找出工程项目J2使用的各种零件的名称及其数量
+SELECT P.PNAME AS 零件名称, SUM(SPJ.QTY) AS 总数量
+FROM SPJ
+         JOIN P ON SPJ.PNO = P.PNO
+WHERE SPJ.JNO = 'J2'
+GROUP BY P.PNAME;
+Go
+-- 找出上海厂商供应的所有零件号码
+SELECT DISTINCT SPJ.PNO
+FROM SPJ
+         JOIN S ON SPJ.SNO = S.SNO
+WHERE S.CITY = N'上海';
+Go
+-- 找出使用上海产的零件的工程名称
+SELECT DISTINCT J.JNAME
+FROM SPJ
+         JOIN S ON SPJ.SNO = S.SNO
+         JOIN J ON SPJ.JNO = J.JNO
+WHERE S.CITY = N'上海';
+Go
+-- 找出没有使用天津产的零件的工程号码
+SELECT JNO
+FROM J
+WHERE JNO NOT IN (SELECT DISTINCT SPJ.JNO
+                  FROM SPJ
+                           JOIN S ON SPJ.SNO = S.SNO
+                  WHERE S.CITY = N'天津');
+Go
+-- 把全部红色零件的颜色改成蓝色
+UPDATE P
+SET COLOR = N'蓝'
+WHERE COLOR = N'红';
+SELECT PNO, COLOR
+FROM P; -- Validate
+Go
+-- 将S5供给J4的零件P6改为由S3供应
+UPDATE SPJ
+SET SNO = 'S3'
+WHERE SNO = 'S5'
+  AND JNO = 'J4'
+  AND PNO = 'P6';
+SELECT *
+FROM SPJ
+WHERE JNO = 'J4'
+  AND PNO = 'P6'; -- Validate
+Go
+-- 删除供应商S2及相关供应记录
+DELETE
+FROM SPJ
+WHERE SNO = 'S2'; -- 先删除SPJ表中S2的供应记录
+DELETE
+FROM S
+WHERE SNO = 'S2'; -- 再删除S表中的S2记录
+SELECT SNO
+FROM S; -- Validate: S2 已不存在
+SELECT SNO
+FROM SPJ; -- Validate: S2 相关记录已删除
+Go
+-- 插入供应情况记录 (S2,J6,P4,200)
+INSERT INTO SPJ (SNO, PNO, JNO, QTY)
+VALUES ('S2', 'P4', 'J6', 200);
+SELECT *
+FROM SPJ
+WHERE SNO = 'S2'
+  AND JNO = 'J6'
+  AND PNO = 'P4'; -- Validate
+Go