diff --git "a/40\345\274\240\350\200\200\344\273\201/\344\275\234\344\270\232/0927\344\275\234\344\270\232.sql" "b/40\345\274\240\350\200\200\344\273\201/\344\275\234\344\270\232/0927\344\275\234\344\270\232.sql"
new file mode 100644
index 0000000000000000000000000000000000000000..e1d3d4d0550dfaae61202d04dc463e9a4193e554
--- /dev/null
+++ "b/40\345\274\240\350\200\200\344\273\201/\344\275\234\344\270\232/0927\344\275\234\344\270\232.sql"
@@ -0,0 +1,62 @@
+--编写视图实现查询出所有银行卡账户信息，显示卡号，身份证，姓名，余额。
+create view V_AIfo(卡号,身份证,姓名,余额)
+as
+select b.CardNo,a.AccountCode,a.RealName,b.CardMoney from AccountInfo a
+inner join BankCard b on a.AccountId = b.AccountId
+go
+
+select * from V_AIfo
+
+create table [mod] (
+	[year] int,
+	[month] int,
+	amount float
+)
+insert into [mod] values
+(1991,1,1.1),
+(1991,2,1.2),
+(1991,3,1.3),
+(1991,4,1.4),
+(1992,1,2.1),
+(1992,2,2.2),
+(1992,3,2.3),
+(1992,4,2.4)
+go
+
+--列转行
+select [year],
+max(case when [month] = 1 then amount else 0 end) m1,
+max(case when [month] = 2 then amount else 0 end) m2,
+max(case when [month] = 3 then amount else 0 end) m3,
+max(case when [month] = 4 then amount else 0 end) m4
+ from [mod] 
+group by [year]
+
+
+select * from [mod] 
+pivot
+(
+sum(amount)
+for [month] in ([1],[2],[3],[4])
+) as amount
+
+
+CREATE TABLE Sales(
+[Year] INT,
+A1 INT,
+A2 INT,
+A3 INT,
+A4 INT);
+GO
+INSERT INTO Sales VALUES 
+(2017,12,123,324,123),
+(2018,13,455,324,878),
+(2019,29,786,473,633);
+--行转列
+select [Year],'A1' as peopel,A1 as Amonut from Sales union all
+select [Year],'A2' as peopel,A2 as Amonut from Sales union all
+select [Year],'A3' as peopel,A3 as Amonut from Sales union all
+select [Year],'A4' as peopel,A4 as Amonut from Sales
+
+select * from Sales
+unpivot (Amount for people in (A1,A2,A3,A4)) as a
\ No newline at end of file
diff --git "a/40\345\274\240\350\200\200\344\273\201/\347\254\224\350\256\260/0927\347\254\224\350\256\260\302\267.txt" "b/40\345\274\240\350\200\200\344\273\201/\347\254\224\350\256\260/0927\347\254\224\350\256\260\302\267.txt"
new file mode 100644
index 0000000000000000000000000000000000000000..cc02c590460190316e6de1dff6bef842fcb6176d
--- /dev/null
+++ "b/40\345\274\240\350\200\200\344\273\201/\347\254\224\350\256\260/0927\347\254\224\350\256\260\302\267.txt"
@@ -0,0 +1,49 @@
+1.瑙嗗浘
+1.1瑙嗗浘鐨勬杩�
+璇曞浘锛坴iew锛夋槸鏁版嵁搴撲腑鐨勪竴涓璞★紝瀹冩槸鏁版嵁搴撶鐞嗙郴缁熸彁渚涚粰鐢ㄦ埛鐨勪互澶氱瑙掑害瑙傚療鏁版嵁搴撲腑鏁版嵁鐨勪竴绉嶉噸瑕佹満鍒躲�傚畠瀵瑰簲涓夌妯″紡涓殑澶栨ā寮忋��
+
+鍦⊿QL涓紝璇曞浘鏄熀浜嶴QL璇彞鐨勭粨鏋滈泦鐨勫彲瑙嗗寲鐨勮〃銆�
+
+瑙嗗浘鍖呭惈琛屽拰鍒楋紝灏卞儚涓�涓湡瀹炵殑琛ㄣ�傝鍥句腑鐨勫瓧娈靛氨鏄潵鑷竴涓垨澶氫釜鏁版嵁搴撲腑鐨勭湡瀹炵殑琛ㄤ腑鐨勫瓧娈点�備絾瑙嗗浘涓庡熀鏈〃涓嶅悓锛岃瘯鍥炬槸涓�涓櫄琛ㄣ�傛暟鎹簱涓彧瀛樺偍瑙嗗浘鐨勫畾涔夛紝鑰屼笉瀛樺偍瑙嗗浘鎵�鍖呭惈鐨勬暟鎹紝杩欎簺鏁版嵁浠嶅瓨鏀惧湪鍘熸潵鐨勫熀鏈〃涓�傝繖绉嶆ā寮忔湁涓や釜濂藉锛�
+
+瑙嗗浘鏁版嵁濮嬬粓涓庡熀鏈〃鏁版嵁淇濇寔涓�鑷达紝褰撳熀鏈〃鍙戠敓鍙樺寲鏃讹紝浠庤鍥句腑鏌ヨ鍑虹殑鏁版嵁涔熶細闅忎箣鍙樺寲銆� 鑺傜渷瀛樺偍绌洪棿銆傚綋鏁版嵁閲忛潪甯稿ぇ鏃讹紝閲嶅瀛樺偍鏁版嵁闈炲父鑰楄垂绌洪棿銆� 瑙嗗浘鍙互浠庝竴涓熀鏈〃涓彁鍙栨暟鎹紝涔熷彲浠ヤ粠澶氫釜鍩烘湰琛ㄤ腑鎻愬彇鏁版嵁锛岀敋鑷宠繕鍙互浠庡叾浠栬鍥句腑鎻愬彇鏁版嵁锛屽悎鐞嗗埄鐢ㄥ彲浠ュ甫鏉ュ緢澶氬ソ澶勶細
+
+绠�鍖栨暟鎹煡璇€�� 浣跨敤鎴疯兘澶熶粠澶氳搴︾湅寰呭悓涓�鏁版嵁銆� 鎻愰珮鏁版嵁鐨勫畨鍏ㄦ�с�� 鎻愪緵浜嗕竴瀹氱▼搴︾殑閫昏緫鐙珛鎬с��
+
+CREATE VIEW <瑙嗗浘鍚�> [(鍒楀悕 [, ...n])]
+AS
+	SELECT璇彞
+SELECT璇彞涓�氬父涓嶅寘鍚玂RDER BY 鍜孌ISTINCT瀛愬彞
+鍦ㄥ畾涔夎鍥炬椂瑕佷箞鍒跺畾瑙嗗浘鐨勫叏閮ㄥ垪鍚嶏紝瑕佷箞鍏ㄩ儴鐪佺暐涓嶅啓锛屼笉鑳藉彧鍐欒鍥剧殑閮ㄥ垎鍒楀悕銆�
+2.琛岃浆鍒楀拰鍒楄浆琛�
+2.1琛岃浆鍒�
+2.1.1 case when 浠ュ強 sum/max
+select [year],
+max(case when [month] = 1 then amount else 0 end) m1,
+max(case when [month] = 2 then amount else 0 end) m2,
+max(case when [month] = 3 then amount else 0 end) m3,
+max(case when [month] = 4 then amount else 0 end) m4
+ from [mod] 
+group by [year]
+2.1.2 pivot
+select * from [mod]  --1
+pivot
+(
+sum(amount)  --3
+for [month] in ([1],[2],[3],[4])  --2
+) as amount
+
+
+--1鏁版嵁鏉ユ簮
+--2閭ｄ簺鍊煎仛鏂板垪鐨勫悕瀛�
+--3瀵规柊鍒楃殑鍊肩殑瑕佹眰
+2.2鍒楄浆琛�
+2.2.1union
+select [Year],'A1' as peopel,A1 as Amonut from Sales union all
+select [Year],'A2' as peopel,A2 as Amonut from Sales union all
+select [Year],'A3' as peopel,A3 as Amonut from Sales union all
+select [Year],'A4' as peopel,A4 as Amonut from Sales
+2.2.2 unpivot
+
+select * from Sales
+unpivot (Amount for people in (A1,A2,A3,A4)) as a
\ No newline at end of file