Many database professionals have a hard time writing complex, complicated or advanced SQL queries for the following reasons.
In a healthcare database project that I consulted on, I had to write fairly complicated and efficient SQL queries for physicians at several practices because of their specialized reporting requirements.
The real problem was not the complexity of the physicians database but it’s poor suitability to the physicians reporting needs.
Based on experience gathered from consulting on several database or data analysis projects, I have observed that writing complex or complicated SQL queries, may prove challenging because of the following:
Quick and Dirty Database Design: you inherited a bad relational database design and because of that, it takes a number of complex or fairly complicated SQL queries to get answers out of your data.
For some reason, the database was developed without sufficient thought or planning, limiting the organization’s ability to access its data!
Over Normalized Database: you created a perfectly normalized textbook database but now, you need a large number of table joins to access the operational data needed by your organization on a regular basis.
Changing Reporting Requirements: the data reporting needs of your organization has grown but your database design has not changed.
For some reason, you cannot update your database design, so you resort to tasking your database with complex or complicated SQL query statements in a bid to extract answers that it’s not originally designed to report.
Complex Data Reporting Requirements: The data reporting requirements of your organization are truly complex and it will typically take a complex amount of SQL query statements to get at your data regardless of how well one designs the relational database.
Poor Reporting Requirements: In some cases, complicated SQL queries are written because the data is not well known or understood.
This is fairly common when SQL queries are written against a large relational data model without understanding the data or relationships between tables in the data model.
This may also happen when a database developer joins several tables in complex subqueries without realizing that the information could be retrieved from a smaller set of tables.
Basic SQL Writing Skills: database developers unaware of the limitations of their SQL query writing skills, may attempt to write SQL queries beyond their skill level.
This may happen when you are tasked with writing complicated SQL queries without adequate training.
For example, business analysts, computer programmers or reporting analysts write SQL queries even though that may not be part of their primary functions!
Writing SQL Queries can get complex or complicated if you don’t fully understand what you are dealing with.
To succeed, you need a good understanding of your data, good requirements, strong relational database design as well as strong SQL query writing skills.
Don’t settle for anything less than a clear understanding of your challenge and a strong set of skills for dealing with it!
If you are facing the challenge of writing complex or complicated sql queries, consider a SQL Training Program like the SQLBootCamp where you are taken step by step through the entire SQL Query Writing process … starting from creating a normalized relational databases to writing basic or advanced sql queries!
Just so, you know, SQLBootCamp Online Training can help you Get Started Writing Complex Or Efficient SQL Queries.