One of the first steps in data analysis is examining data through aggregations. This chapter explores how to create aggregations in SQL Server, a common first step in data exploration. You will also clean missing data and categorize data into bins with CASE statements.

Data analysis with aggregations

Creating aggregations

Creating grouped aggregations

Dealing with missing data

Removing missing values

Imputing missing values (I)

Imputing missing values (II)

Binning data with CASE

Using CASE statements

Creating several groups with CASE

Summarizing Data

This chapter explores essential math operations such as rounding numbers, calculating squares and square roots, and counting records. You will also work with dates in this chapter! 

Counting and totals

Calculating the total

Counting the number of rows

Dates

Which date function should you use?

Counting the number of days between dates

Adding days to a date

Rounding and truncating

Rounding numbers

Truncating numbers

More math functions

Calculating the absolute value

Calculating squares and square roots

Math Functions

In this chapter, you will create variables and write while loops to process data. You will also write complex queries by using derived tables and common table expressions. 

WHILE-lussen

Variabelen maken en gebruiken

Een WHILE-lus maken

Afgeleide tabellen

Query's met afgeleide tabellen (I)

Queries met afgeleide tabellen (II)

Common Table Expressions

CTE-syntaxis

CTE's maken (I)

CTE's maken (II)

Processing Data in SQL Server

In the final chapter of this course, you will work with partitions of data and window functions to calculate several summary stats and see how easy it is to create running totals and compute the mode of numeric columns.

Window functions in T-SQL

Window functions with aggregations (I)

Window functions with aggregations (II)

Common window functions

Do you know window functions?

First value in a window

Previous and next values

Increasing window complexity

Creating running totals

Assigning row numbers

Using windows for statistical functions

Calculating standard deviation

Calculating mode (I)

Calculating mode (II)

Window Functions

Incidents

Shipments

Kidney

Orders

De meeste data wordt opgeslagen in databases. Weten hoe je data direct in databases kunt analyseren en opschonen is daarom onmisbaar. Deze cursus richt zich op T-SQL, de SQL-variant die wordt gebruikt in Microsoft SQL Server en die je nodig hebt voor data-analyse. Je leert verschillende concepten, zoals omgaan met ontbrekende waarden, werken met datums en het berekenen van samenvattende statistieken met geavanceerde queries. Na het afronden van deze cursus heb je de vaardigheden om data snel en eenvoudig te analyseren en inzichten te leveren.

Introduction to SQL Server

Leer T-SQL-concepten zoals omgaan met ontbrekende data, werken met data en geavanceerde query's.

SQL Server voor gevorderden

SQL Server-ontwikkelaar

SQL Server-basisprincipes

CTE-syntaxis

SQL Server voor gevorderden

Praktische interactieve oefening