5 Best Database Tips for Beginners

SQL Forms the Core of Relational Databases

The Structured Query Language (SQL) forms the core of all relational databases. It provides a uniform interface to Oracle, SQL Server, Microsoft Access, and other relational databases and is a "must learn" for all aspiring database users.

Take an introductory SQL course before you attempt to learn any specific database software. The time investment will help you build a proper foundation and get started on the correct foot in the world of databases.

Selecting Primary Keys Is an Important Decision

The selection of a primary key is one of the most critical decisions you'll make while designing a new database. The most important constraint is that you must ensure that the selected key is unique.

If one value attribute may be in two records, the shared attribute is a poor choice for a primary key. You should probably also avoid sensitive values that raise privacy concerns, such as Social Security numbers.

NULL Is Not Zero or the Empty String

NULL is a special value in the world of databases, but it's something that often confuses beginners.

When you see a NULL value, interpret it as "unknown." For example, if a quantity is NULL, that doesn't necessarily mean that it's zero. Similarly, if a text field holds a NULL value, it doesn't mean that there isn't an appropriate value—it's simply unknown.

Consider a database containing information about children who attend a particular school. If the person entering the record doesn't know a student's age, a NULL value is used to indicate the "unknown" placeholder. The student certainly has an age; it's just not present in the database.

Converting Spreadsheets to Databases Saves Time

If you have tons of data stored in Microsoft Excel or another spreadsheet format, you can save yourself time by converting those spreadsheets into database tables.