SQL Development
SQL development that turns the questions you keep asking your data into fast, reliable queries, views, and reports. Whether you need a stubborn query fixed, a reporting layer built, or slow queries made quick, I write SQL that is correct, efficient, and clear enough for the next person to maintain.
SQL is the language your data actually speaks, and the gap between a query that works and one that works well is enormous. A poorly written query can be slow, subtly wrong, or impossible for anyone else to maintain, and businesses run on these queries every day without realizing how much a better one would save them. SQL development is the craft of writing queries that are correct, fast, and clear, so the answers you pull from your data can be trusted and the reports built on them do not grind.
I am a Microsoft Certified Power BI Data Analyst (PL-300) and a Fabric Analytics Engineer (DP-600), and I have written the T-SQL that powers a layered enterprise warehouse, from gold-layer views exposed for ad-hoc querying to the transformations underneath. Here is how I approach SQL development.
What SQL development covers
SQL development is the work of writing and improving the queries, views, stored procedures, and reporting logic that get data out of your database and into a usable form. In practice it spans a wide range: answering specific business questions with a well-built query, creating reusable views and procedures that package complex logic, building the reporting layer that feeds dashboards, and tuning slow queries so they return in seconds rather than minutes. Wherever data lives in a relational database, SQL is how you get real value out of it.
What separates good SQL from merely working SQL is correctness, performance, and clarity, in that order. A query has to return the right answer, which is harder than it sounds once joins, filters, and aggregations combine in ways that quietly double-count or drop rows. It has to run efficiently, because a query that is correct but slow still blocks the work. And it has to be readable, so the next person, or you in six months, can understand and safely change it rather than being afraid to touch it.
WHAT YOU GET
Queries that are
right and fast.
Correct, efficient, readable SQL, from one-off answers to a full reporting layer.
- Queries that answer the questionThe specific answers you need pulled correctly, with the joins and aggregations built so they do not quietly double-count or drop rows.
- Reusable views and proceduresComplex logic packaged into views and stored procedures, so the hard part is written once and reused rather than rebuilt each time.
- A clean reporting layerThe SQL that feeds your dashboards built properly, so reports are fast and consistent instead of dragging on tangled underlying queries.
- Faster slow queriesSluggish queries diagnosed and tuned, through better logic and indexing, so they return in seconds rather than blocking the work.
- Readable, maintainable codeSQL written clearly and documented, so the next person can understand and safely change it rather than being afraid to touch it.
How I approach SQL work
Whether it is one query or a reporting layer, the method is the same: get it right, make it fast, keep it clear.
Understand the question and the data. I start with exactly what you need to know and how your tables actually relate, because most wrong queries come from a misunderstanding of the data, not the syntax.
Write it correctly first. I build the query to return the right answer, being careful with the joins and aggregations that quietly corrupt results, and I check it against known figures rather than trusting that it looks right.
Then make it fast. Once it is correct, I tune it, rewriting inefficient logic and adding the right indexes, so it performs well at real data volumes rather than only on a small sample.
Package for reuse. Where the logic will be needed again, I build it into views or stored procedures, so it is written once and reused consistently instead of copied and diverging over time.
Document and hand over. I write the SQL to be read, with comments where the logic is non-obvious, so your team can maintain and extend it confidently rather than working around a black box.
Why good SQL is worth paying for
It is easy to assume SQL is SQL, that any query returning numbers is doing its job. The trouble is that a wrong query returns numbers too, confidently, and a subtle join error that double-counts revenue will not announce itself; it just quietly inflates every report downstream until someone notices the totals never reconcile. Correctness in SQL is not a given, and getting it genuinely right is a large part of the value.
Performance is the other half. A slow query is not just an inconvenience; it caps how usable the reporting on top of it can be, and it often traces to logic that could be rewritten to run many times faster. Fixing that is frequently the cheapest large win available, because the same answer arrives in seconds instead of minutes without changing anything the user sees. Correct, fast, readable SQL is quiet infrastructure: you notice its absence far more than its presence, which is exactly why it repays doing well.
There is a maintainability angle that is easy to undervalue until it bites. A clever query that only its author understands becomes a liability the moment that person moves on, because the next person is left afraid to change something they cannot follow. I write for the reader as much as the machine, clear structure, sensible names, and a comment where the logic is genuinely non-obvious, so the code can be picked up and safely extended by whoever inherits it. That readability costs a little time up front and saves a great deal later, which is a trade worth making on anything the business will rely on for more than a week.
Timeline and cost
SQL work scales with the task. A single tricky query or a slow one that needs tuning can often be sorted in hours to a day. A reporting layer or a set of views and procedures over a real schema takes longer, because the value is in getting the logic correct and performant rather than rushing something that looks right but is not.
Judge the cost against what wrong or slow queries cost you: reports that never reconcile, decisions on inflated numbers, and time lost waiting on queries that could run in seconds. Good SQL removes all three. For Microsoft's T-SQL reference, see Microsoft Learn. Clean, fast, reliable SQL is the layer that decides whether everything you build on your database can be trusted.
Frequently asked questions
What does SQL development cover?
It covers writing and improving the queries, views, stored procedures, and reporting logic that get data out of a relational database. That spans answering specific business questions, packaging complex logic into reusable views and procedures, building the reporting layer behind dashboards, and tuning slow queries so they return quickly.
Can you fix a query that returns the wrong numbers?
Yes, and it is common work. Wrong results usually come from joins or aggregations that quietly double-count or drop rows, or from a misunderstanding of how the tables relate. I trace the logic, correct it, and check it against known figures, so the query returns the right answer rather than a plausible-looking wrong one.
My queries are slow. Can you make them faster?
Usually, significantly. Slow queries often come from inefficient logic or missing indexes rather than the data volume itself. I diagnose where the time goes, rewrite the logic, and add the right indexing, so the same answer returns in seconds instead of minutes, which often lifts every report built on that query.
Should logic live in SQL views or in Power BI?
It depends, but heavy or shared logic usually belongs in SQL views so it is written once, runs close to the data, and feeds every report consistently. Keeping the reporting layer clean in SQL makes dashboards faster and simpler. I help decide where each piece of logic best sits for performance and maintainability.
Which databases do you work with?
I work primarily with SQL Server and T-SQL, including the warehouse in Microsoft Fabric, and the core skills carry across relational databases. The dialect differs a little between systems, but the discipline, correct logic, good performance, and readable code, is the same wherever the data lives.
Can you build a reporting layer for our dashboards?
Yes. I build the SQL views and procedures that feed dashboards, so the reporting reads from clean, consistent, well-performing logic rather than tangled ad-hoc queries. A proper reporting layer makes dashboards faster and the numbers consistent, and it is a natural companion to data warehouse and Power BI work.
Stuck on a query, or a slow one?
Tell me what you need from your database, and I will write the SQL that answers it correctly and quickly.