Unit 8: Introduction to SQL
Structured Query Language (SQL) is the main data definition language used for the creation and maintenance of databases. In this unit, we will look at basic SQL syntax, including some data definition and data manipulation language commands. When developing or using a database, we have to consider how the data should be organized so that it is stored and accessed efficiently, and how needed information can be found. If the data is for a specific application, the solutions would be based on knowledge of the application domain. However, a database is a common system used for many applications, and thus many solutions need to be generic. Relational algebra, relational calculus, and normalization help address these problems.
The evolution from a specific solution to a general solution is similar to the evolution from a special-purpose to a general-purpose computer, which was accomplished by the development of programming languages. In a similar manner, database languages implement the creation of databases and access of information for many applications, which allows us to use databases as a common component for many applications and types of systems.
Completing this unit should take you approximately 5 hours.
8.1: What is SQL?
8.2: Data Definition Language (DDL)
8.3: Column- and Table-Level Constraints
8.4: Data Manipulation Language (DML)
Unit 8 Assessment