What is Big Data?

I hear the term “big data” being thrown around all the time now. “We have big data.” “We want big data.” “We need to develop a big data solution.” I believe that anything that gets people talking about data and its various applications is a positive. That being said, when most people say “big data” […]

SQL Aggregate Functions

SQL Aggregate Functions

What are SQL Aggregate Functions? Aggregate functions are functions that aggregate values and output a scalar (single-row) value as the result. Examples of aggregate functions include the COUNT, SUM, AVG, MIN, and MAX functions. For example, to find the total number of rows in the Person.Person table, we can use the query: SELECT COUNT(*) FROM […]

SQL ORDER BY

Using the SQL ORDER BY Clause

How do I sort data with the SQL ORDER BY clause? Sorting returned data is a very common task when completing SQL statements. Luckily, the SQL ORDER BY clause allows us to complete this activity pretty easily. For example, to return the the FirstName and LastName columns from Person.Person sorted by the FirstName column in […]

SQL Comparison Operators

SQL Comparison Operators

What are the different SQL Comparison Operators? In previous lessons, we have discussed many of the different SQL comparison operators that are available. These operators give you plenty of options to filter data in the WHERE clause of your SELECT statement. Having discussed many of them, I want there to be one consolidated place for […]

SQL Wildcard Operators and the LIKE Operator

SQL Wildcard Operators and the LIKE Operator

What is the LIKE operator? The LIKE operator is an operator that allows you to use SQL wildcard operators in the WHERE clause. SQL wildcard operators along with the LIKE operator allow you to search for patterns of strings. For example, to find all rows in the Person.Person table where the FirstName column starts with […]

SQL BETWEEN Operator in SQL WHERE Clause

SQL WHERE Clause BETWEEN Operator

What is the BETWEEN operator? The BETWEEN operator is a logical operator that allows you to search for data between two values. In previous lessons to find all rows in Production.Product where the ListPrice was between 100 and 200, we wrote the query: SELECT * FROM Production.Product WHERE ListPrice >= 100 AND ListPrice

SQL WHERE Clause IN Operator

SQL WHERE Clause IN Operator

What is the IN operator? The IN operator is a logical operator that can be used in the WHERE clause to filter based on a list of values. For example, using only the information learned in the previous lessons, if we wanted to return all rows in the Person.Person table where the FirstName is either […]

data visualization

Why You Need Data Visualization

A critical component of a successful business intelligence strategy involves the use and embrace of data visualization. As we shift our primary reporting tool from Excel to a true business intelligence solution, this will become less of a “want to have” and more of a “need to have”. What is Data Visualization? Data visualization is […]

SQL WHERE with NULL

Using the SQL WHERE Clause – Part 4

How I do use the SQL WHERE clause for NULL values? NULL is something you might see in the database quite a bit. NULL means there is no value. This is not a blank value – like a blank space – but truly nothing. This is a subtle but important difference. Those with some programming […]

SQL WHERE clause with dates

Using the SQL WHERE Clause – Part 3

How do I use the SQL WHERE clause with dates? Using the WHERE clause with dates is very similar to filtering text. Date values must be enclosed with the single apostrophe. To find all rows that have an OrderDate equal to July 15, 2005 in the Sales.SalesOrderHeader table, we use the query: SELECT * FROM […]