t500zhuyu/data_cleaning_covid_data

This a data cleaning and queries using Microsoft SQL Server The data set is from: https://ourworldindata.org/

In this script I use different statements to check and analyze info. SQL keywords are like:

select from

where

order by

MAX

SUM

JOIN

DROP

Insert Into Breaking out address into individual columns using: SUBSTRING, CHARINDEX Updating the table Split columns to divide the info, for example an address, statements used: PARSENAME, REPLACE Changing info of the columns using case when, when, else, end Remove duplicates using ROW_NUMBER Using CTE (Common Table Expression)