Add initial docs 'Coming from SQL'

Documentation/Books/HTTP/Document/AddressAndEtag.mdpp

@@ -19,17 +19,17 @@ Here is an example document:
 {
   "_id" : "myusers/3456789",
   "_key" : "3456789",
-  "_rev" : "3456789",
+  "_rev" : "14253647",
-  "firstName" : "Hugo",
+  "firstName" : "John",
-  "lastName" : "Schlonz",
+  "lastName" : "Doe",
   "address" : {
-    "street" : "Street of Happiness",
+    "street" : "Road To Nowhere 1",
-    "city" : "Heretown"
+    "city" : "Gotham"
   },
   "hobbies" : [
-    "swimming",
+    {name: "swimming", howFavorite: 10},
-    "biking",
+    {name: "biking", howFavorite: 6},
-    "programming"
+    {name: "programming", howFavorite: 4}
   ]
 }
 ```

Documentation/Books/Users/DataModeling/Documents/DocumentAddress.mdpp

@@ -13,21 +13,21 @@ Any transaction only ever sees a single revision of a document.
 For example:
 
 ```js
-{ 
+{
-  "firstName" : "Hugo", 
+  "_id" : "myusers/3456789",
-  "lastName" : "Schlonz", 
+  "_key" : "3456789",
-  "address" : { 
+  "_rev" : "14253647",
-    "city" : "Hier", 
+  "firstName" : "John",
-    "street" : "Strasse 1" 
+  "lastName" : "Doe",
-  }, 
+  "address" : {
-  "hobbies" : [ 
+    "street" : "Road To Nowhere 1",
-    "swimming", 
+    "city" : "Gotham"
-    "biking", 
+  },
-    "programming" 
+  "hobbies" : [
-  ], 
+    {name: "swimming", howFavorite: 10},
-  "_id" : "demo/schlonz", 
+    {name: "biking", howFavorite: 6},
-  "_rev" : "13728680", 
+    {name: "programming", howFavorite: 4}
-  "_key" : "schlonz" 
+  ]
 }
 ```
 

Documentation/Books/Users/GettingStarted/ComingFromSql.mdpp

@@ -0,0 +1,117 @@
+!CHAPTER Coming from SQL
+
+!SUBSECTION How do browse vectors translate into document queries?
+
+In traditional SQL you may either fetch all columns of a table row by row, using
+`SELECT * FROM table`, or select a subset of the columns. The list of table
+columns to fetch is commonly called *column list* or *browse vector*:
+
+```sql
+SELECT columnA, columnB, columnZ FROM table
+```
+
+Since documents aren't two-dimensional, and neither do you want to be limited to
+returning two-dimensional lists, the requirements for a query language are higher.
+AQL is thus a little bit more complex than plain SQL at first, but offers much
+more flexibility in the long run. It lets you handle arbitrarily structured
+documents in convenient ways, mostly leaned on the syntax used in JavaScript.
+
+!SUBSUBSECTION Composing the documents to be returned
+
+The AQL `RETURN` statement returns one item per document it is handed. You can
+return the whole document, or just parts of it. Given that *oneDocument* is
+a document (retrieved like `LET oneDocument = DOCUMENT("myusers/3456789")`
+for instance), it can be returned as-is like this:
+
+```js
+RETURN oneDocument
+
+```json
+[
+    {
+        "_id" : "myusers/3456789",
+        "_key" : "3456789"
+        "_rev" : "14253647",
+        "firstName" : "John",
+        "lastName" : "Doe",
+        "address" : {
+            "city" : "Gotham",
+            "street" : "Road To Nowhere 1"
+        },
+        "hobbies" : [
+            {name: "swimming", howFavourite: 10},
+            {name: "biking", howFavourite: 6},
+            {name: "programming", howFavourite: 4}
+        ]
+    }
+]
+```
+
+Return the hobbies sub-structure only:
+
+```js
+RETURN oneDocument.hobbies
+```
+
+```json
+[
+    [
+        {name: "swimming", howFavourite: 10},
+        {name: "biking", howFavourite: 6},
+        {name: "programming", howFavourite: 4}
+    ]
+]
+```
+
+Return the hobbies and the address:
+
+```js
+RETURN {
+    hobbies: oneDocument.hobbies,
+    address: oneDocument.address
+}
+```
+
+```json
+[
+    {
+        hobbies: [
+            {name: "swimming", howFavourite: 10},
+            {name: "biking", howFavourite: 6},
+            {name: "programming", howFavourite: 4}
+        ],
+        address: {
+            "city" : "Gotham",
+            "street" : "Road To Nowhere 1"
+        }
+    }
+]
+```
+
+Return the first hobby only:
+
+```js
+RETURN oneDocument.hobbies[0].name
+```
+
+```json
+[
+    "swimming"
+]
+```
+
+Return a list of all hobby strings:
+
+```js
+RETURN { hobbies: oneDocument.hobbies[*].name }
+```
+
+```json
+[
+    {hobbies: ["swimming", "biking", "porgramming"] }
+]
+```
+
+More complex [array](../../AQL/Functions/Array.md) and
+[object manipulations](../../AQL/Functions/Document.md) can be done using
+AQL functions and [operators](../../AQL/Operators.md).