2022-Basics of SQL using PostgreSQL

We learn how to select some or all columns from a single table. Learn about aliases for column names.

We see some more uses of the SELECT keyword and use aliases to change column names using the AS keyword.

Explain what an INNER JOIN is and why we need it and how it works.

A practical example of an INNER JOIN.

We look at an example where we need to join more than two tables.

Explains what are outer joins, why we need them and examples.

Explain what a self join is and two examples where we can use them.

In this video we look at some basic datatypes in SQL such as VARCHAR, CHAR, INT and REAL (and their variations).

We group our rows into groups based on distinct values of a column and get data about the groups.

Since aggregate calculations are very important, we take a deeper look into when exactly these aggregates are calculated.

We group our rows using more than one column and data that is not immediately available in the table as a simple column.

We look at how we can combine multiple types of grouping operations into a single SQL query and how we read the result set.

Here we look at ways to combine multiple tables with compatible datatypes using SET type operations: UNION, INTERSECT and EXCEPT.

Here we look at ways that we can use a sub-query which is essentially feeding the result set of one query to another.

We use the CASE statement along with WHEN, THEN to produce results based on the values of a column.

We explore CTEs and apply them to two problems.

We create virtual tables called VIEWS and show how we can use it for ease of use and some security feature.

We discuss MATERIALIZED VIEWS which are nothing but VIEWS with actual data backing them. They can be used as a regular table and are useful for storing results are requested frequently.

In this video, we introduce TRANSACTIONS and explore the need and how to implement them.

We look at implicit and explicit transactions and explore reasons to use explicit transactions.