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joplin notion extension/Web Development/NOSQL/mongodb/Theory.md

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+Theory
+https://www.youtube.com/playlist?list=PL4cUxeGkcC9h77dJ-QJlwGlZlTd4ecZOA
+
+- relational database
+  1 author can have many books whose information are stored in the other table named Books.
+  ![9a6a085c63fcaeb121f425de0d03d4b0.png](../../../../_resources/9a6a085c63fcaeb121f425de0d03d4b0.png)
+  So we have rows,columns, table and joining 
+  Columns is property
+  and we use sql queries to use them
+  
+  
+- non relational database
+  Here instead of rows, columns and tables we use collections and documents
+  Each collection store a specific type of  data record like users, authors and books.These records inside collections are called documents
+  So users is collection unlike table in sql. and instead of containing columns and rows it contains document which is more like js object
+  ![2edcc32c60246452cda407c2da2e3c18.png](../../../../_resources/2edcc32c60246452cda407c2da2e3c18.png)
+  Here author field has nested object. in sql we would have to use other table for that.
+  
+**Installation**
+- In arch use
+  `yay -S mongodb-bin` this will install mongodb server and mongodb shell. Make sure to start mongodb service too by 
+  `systemctl start mongodb`
+  also install mongodb-tools. `mongodb-org-tools` in case of debian and `mongodb-tools-bin` from aur in case of arch. it is for import, export and other diagonistic tools
+ 
+- in linux mint/ubuntu
+   https://www.mongodb.com/docs/v7.0/tutorial/install-mongodb-on-ubuntu/#std-label-install-mdb-community-ubuntu
+  
+
+**Collections and Documents**
+![1a819c18ab7dea9f21918c9abcfae274.png](../../../../_resources/1a819c18ab7dea9f21918c9abcfae274.png)
+Mongodb stores data in BSON which is Binary JSON and returns result in JSON.
+Each document has a property `_id` which is assigned automatically by mongodb and its data type is 'ObjectId'.
+