SQL Basics

by Arnold Quarcoo

When using SQL (Structured Query Language), the order of operation is very important. Below is the order of operation to help you get it write:

  1. Select -  This is similar to the select tool within Alteryx, in that it allows us to select the specific data we require from the database.

Syntax: SELECT ”column_name” or SELECT DISTINCT “column_name” which allows you to return only different values.

Example: SELECT * - The asterisk selects all the data from your data source.

2. From - Specify which table to select data from.

Syntax: FROM ”table_name”

Example: FROM "Superstore_Orders"

3. Where - This clause is used to extract information for records that fulfill your specific criterion.

Syntax: WHERE “column_name” operator value;

Example: WHERE “Region” = 'Central' and “Sales” > 1000

4. Group By - Similar to the summarise tool in Alteryx in that it allows us to aggregate to the dimension level.

Syntax: GROUP BY column_name

Example: GROUP BY "State"

5. Having - Similar to the WHERE clause for but for aggregated functions.

Syntax: aggregate_function(column_name) operator value

Example: HAVING AVG ("Profit") > 500

6. Order By - Used to sort the result set in ascending or descending order.

Syntax: ORDER BY column_name DESC/ASC

Example: ORDER BY AVG("Profit") DESC

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Arnold Quarcoo

Fri 25 Nov 2022

Wed 23 Nov 2022