5 Best Database Tips for Beginners
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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. 04 of 05
5 Best Database Tips for Beginners
Tips to working with databases
By Mike Chapple Mike Chapple Writer University of Idaho Auburn University Notre Dame Former Lifewire writer Mike Chapple is an IT professional with more than 10 years' experience cybersecurity and extensive knowledge of SQL and database management. lifewire's editorial guidelines Updated on June 17, 2021 Tweet Share Email Tweet Share Email Apps Best Apps Payment Services If you're just getting started with databases, this rundown of the top things you need to know will help you move forward. These facts are guaranteed to make it easier to work with databases and increase productivity. 01 of 05SQL 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. W3Schools.com is a great starting place for beginners interested in SQL. 02 of 05Selecting Primary Keys Is an Important Decision
alexsl / Getty Images 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. 03 of 05NULL 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. 04 of 05