SQL for Beginners 2024  —  Learn SQL Step by Step

A brief overview of databases.

At the end of this section, you will be able to create and or modify the structure of database objects.

At the end of this section, you will be able to modify the data in the database.

At the end of this section, you will be able to access and retrieve data in a database.

At the end of this section, you will be able to offer privilege or access rights to database users to perform certain actions in the database based on their role.

How to install SQL Server on Docker.

How to Install SQL Server on Windows - Follow the step by step instructions attached in order to install SQL Server Developer or Express edition for free from Microsoft. The prerequisite software can be downloaded from Microsoft as instructed.

In this section, we will create the HealthcareDB database to use for the course. Use the SQL CREATE DATABASE script provided to create the database we will use in this section.

In this section, we will create the dummy Patients table to use for the course. Use the SQL CREATE TABLE script provided to create the table we will use in this section.

SQL INSERT INTO statement is used to insert new records into a table.

Run the SQL query to create a dummy Medication table. Execute the attached '8_INSERT_INTO_Medications.sql' script in order to add medication data into the Medication table.

SQL SELECT command is the most widely used command to retrieve data from a database.

SELECT TOP Limits the number of rows returned from a sql statement.

The WHERE clause limit or restricts the SQL query to rows that meet a certain criteria or condition.

SELECT Distinct returns unique results in a data set.

To sort the result set, use the ORDER BY clause - either ASC or DESC (ascending or descending respectively).

To group your result set by specific columns and get one result per group, use the GROUP BY clause.

The HAVING clause is used to further restrict the results of the GROUP BY clause to show records that meet a certain criteria.

The SQL AVG(column) function returns the average value of n, ignoring null values. SQL MIN returns the Minimum value of a selected column. SQL MAX returns the Maximum value of a selected column. The SUM() function returns the total sum of a numeric column, ignoring null values.

The AND operator returns record(s) if all the conditions separated by the AND are TRUE. The OR operator returns record(s) if any of the conditions separated by the OR are TRUE. The SQL NOT returns the opposite condition.

SQL LIKE operator is often used in the WHERE clause in combination with the % percentage and _ underscore symbol(s).

A wildcard character is often used in combination with the SQL LIKE operator to find rows that fit a certain criteria.

The BETWEEN operator returns values within a given range.

The SQL NOT Operator returns the opposite condition.

SQL aliases are used to give a table, or column a temporary name or a different name other than the actual table or column name. The previous exercise shows that you can sort the output by using the alias feature. Therefore, aliases can be used in ORDER BY and GROUP BY clauses.