move Views notes to SQL section

Author: clarklindev

01.SQL.md

@@ -87,6 +87,7 @@
 
 [12. Common table expressions](#12-common-table-expressions)
 [13. Recursive common table expressions (CTE)](#13-recursive-common-table-expressions-cte)
+[14. Views](#14-views)
 
 ---
 ###### <div style="text-align:right">[table of contents](#table-of-contents)</div>
@@ -1450,4 +1451,52 @@ table suggestions (leader_id, follower_id, depth)
 
 ---
 
+###### <div style="text-align:right">[table of contents](#table-of-contents)</div>
+
+## 14. Views
+
+fixing mistakes in the design of table creation process where you constantly have to perform eg. JOINS for queries when you should have maybe had combined tables.
+Better way to merge tables together without deleting original tables.
+
+A view is a "fake" table that has rows from other tables. 
+These can be exact rows or computed values.
+can reference a view in any place where we usually reference a table.
+view doesnt actually create a table or move data around.
+
+Views can be created ahead of time, 
+can be refferenced in different queries (whereas CTE's can only be reffered to in the query they are attached to)
+
+you want to create a view when there is an operation that's logic you will execute often.
+
+view all views -> pgadmin - > schemas -> public views
+
+```SQL
+--creating a view
+CREATE VIEW tags AS(
+	SELECT id, created_at, user_id, post_id, 'photo_tag' AS type FROM photo_tags
+	UNION ALL
+	SELECT id, created_at, user_id, post_id, 'caption_tag' AS type FROM caption_tags
+);
 
+--reference view from another different query
+SELECT username, COUNT(*)
+FROM users
+JOIN tags ON tags.user_id = users.id
+GROUP BY username
+ORDER BY COUNT(*) DESC;
+```
+
+##### updating view (change the definition)
+syntax: CREATE OR REPLACE VIEW _ AS
+
+```SQL
+	CREATE OR REPLACE VIEW recent_posts AS (
+		SELECT * FROM posts
+		ORDER BY created_at DESC
+		LIMIT 15
+	)
+```
+##### deleting a view
+```SQL
+	DROP VIEW recent_posts;
+```

03.postgreSQL.md

@@ -466,50 +466,3 @@ Cost for sequential read =
 (# rows scanned) * cpu_tuple_cost
 
 ---
-
-## Views
-fixing mistakes in the design of table creation process where you constantly have to perform eg. JOINS for queries when you should have maybe had combined tables.
-Better way to merge tables together without deleting original tables.
-
-A view is a "fake" table that has rows from other tables. 
-These can be exact rows or computed values.
-can reference a view in any place where we usually reference a table.
-view doesnt actually create a table or move data around.
-
-Views can be created ahead of time, 
-can be refferenced in different queries (whereas CTE's can only be reffered to in the query they are attached to)
-
-you want to create a view when there is an operation that's logic you will execute often.
-
-view all views -> pgadmin - > schemas -> public views
-
-```SQL
---creating a view
-CREATE VIEW tags AS(
-	SELECT id, created_at, user_id, post_id, 'photo_tag' AS type FROM photo_tags
-	UNION ALL
-	SELECT id, created_at, user_id, post_id, 'caption_tag' AS type FROM caption_tags
-);
-
---reference view from another different query
-SELECT username, COUNT(*)
-FROM users
-JOIN tags ON tags.user_id = users.id
-GROUP BY username
-ORDER BY COUNT(*) DESC;
-```
-
-##### updating view (change the definition)
-syntax: CREATE OR REPLACE VIEW _ AS
-
-```SQL
-	CREATE OR REPLACE VIEW recent_posts AS (
-		SELECT * FROM posts
-		ORDER BY created_at DESC
-		LIMIT 15
-	)
-```
-##### deleting a view
-```SQL
-	DROP VIEW recent_posts;
-```