SQL: How-tos, tips, and tricks for the non-technical professional

As a digital marketer, you’ve no doubt heard about SQL but are unsure what it is or what it does.

Even a non-techie can benefit from a basic understanding of SQL and basic tips and tricks. When developing content, your basic comprehension can help you when working with designers and others in the creation of great sites.

Here are 7 tips and tricks for non-technical types for a better understanding of SQL.

1. Know what SQL is

SQL stands for Structured Query Language. It’s a standard computer language used for accessing and manipulating information in databases.

SQL has multiple applications and is a powerful tool for using and leverages data. It can be used to extract information from a database or insert, update or delete records. It also is used to create new databases or tables within a database.

SQL is also used to store procedures within a database, create views and set permissions.

2. Focus on formatting

Formatting your code makes it cleaner and more readable. It lets you see and debug issues easier. Readability is critical for developing code that is effective and can be used by others. That means not having each action or character on its line. Instead, build code phrases and be consistent in how your code appears.

Case use is another component of good formatting. Use uppercase for SQL clauses and lowercase for tables, columns and field values.

3. Secure your code

Cybersecurity is a persistent threat to all businesses. Keeping data and information secure is essential. That guidance applies to SQL code, too.

Writing secure code varies with each database language. However, MySQL, Oracle and SQL Server all have capabilities that help protect code. SQL injections are one of the most common vectors used to attack websites. By testing your code for security and vulnerability, you can help prevent debilitating attacks that can cripple websites and companies.

4. Know the order of execution

The SQL order of execution is a way to order SQL clauses. The queries built need to follow the standard order of execution to make sense. Developers can run into trouble when they don’t follow the standardized order:

• From – Identifying the tables from which you are sourcing the data
• Where – Filters you are applying to the data extracted
• Group by – Aggregating your data
• Having – Filters you are applying to the data that’s been aggregated
• Select – How you will display the final data
• Order by – Sorting the data for easiest viewing
• Limit – Restrictions on the number of results

When you use the order of execution, your queries will run more effectively.

5. Understanding data types

Not all data are created equally. Each has its own characteristics and features. Among the most common data types are Text, Integer, Date and VarChar (variable characters).

Each of the three main SQL structures has its own data types. For example, in MySQL, there are various categories of data types. These include numeric, date and time, string, spatial and JavaScript Object Notation data types.

For each column of data in your tables, you need to know the proper data types. Developers need to have a full understanding of the data types in use and their characteristics. Otherwise, queries they build will not operate effectively or accurately.

6. Normalize your data

Database normalization helps organize the contents of your databases. Without normalization techniques, databases will be inefficient, inaccurate and slow.

Over the years, the community of database developers has developed a series of normalization standards, called normal forms. Subsequent forms build on those of simpler forms. They frequently rely on keys, which are columns or attributes that identify rows in a table. They forms are:

• First normal form. This most basic form eliminates duplicate columns in a table and creates separate tables for related data
• Second normal form. Uses foreign keys to create relationships between tables
• Third normal form. Removes columns that are not dependent on a primary key and removes derived attributes
• Fourth normal form. Removed multi-valued dependencies from relationships
• Fifth normal form. This rarer form joins dependencies that are implied by certain key types

7. Understand indexing

Database indexes help accelerate operations in a database table. It uses one or more columns within a table helping to speed up lookups and accessing ordered records. Indexing is critically important when working with large tables. It can also be used with smaller tables if the expectation is those tables will grow.

Here’s why indexing matters. When a query is executed on a database, it can be done in two ways to find a matching record. The first and slowest way is to do a table scan, which searches every record in a table to find the match.

The faster way is to do an index scan. Instead of scanning the entire table, it looks at the index columns to find the desired search result.

Indexes need to be rebuilt occasionally, especially as more data are added to a table.

With a basic understanding of SQL, you can help in the design and use of SQL to build better websites and internal systems.