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Nelson chege
Nelson chege

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SQL 101

hi ,welcome to my first technical blog in hopefully a series of more to come. I will be discussing about different topics around technology.

lets talk about SQL.

what is SQL?
the definition of SQL is structured query language.
SQL acts to other similar languages such as JavaScript , python and C++ only that its giving command to the database.

The four most popular SQL commands forms the acronym
CRUD :

  • create
  • read
  • update
  • delete

A database is a collection of organized tables that act similar to excel spread sheet. yeah database are excel spread sheet on some serious steroids.

These database are managed by Database management system that ensure everything is working properly with the database. Some of the available database management system (DBMS) include:

  • PostgreSQL
  • Microsoft sqlserver
  • MySQL
  • oracle.

there are two types of database: relational database and
non-relational database

relational database consist of tables that have relationship between them. Example is when one table has a data that reference data from another table

before forgetting schemas ,a schema is the representation of any kind of structure we are defining around the data that will be inserted into a table

when creating relationship between table you must consider normalization, what is that you ask? this is the structuring of data in the lowest normal that ensure that data is not duplicated across different tables and also more redundancy of data

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