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I will write and fix sql queries for your database
Data Analyst for Excel SQL and Data Cleaning
Ten years cleaning and moving data that has to be right. Most of it at RLDatix, a healthcare contract-management SaaS, where I was Senior Implementation Analyst from 2017 to 2025.
I migrated and reco...
About this Gig
Send me the question in plain English. You get back a query that runs, with comments explaining every step.
The dangerous SQL is not the query that errors. It is the query that returns a number.
A WHERE clause on a LEFT JOIN turns it into an INNER JOIN. No error, and 1,492 customers dropped out of the report.
A join against a table with duplicate keys. Revenue came back three times too high. It still looked like a plausible number.
None of those throw an error. All of them change your answer. So I check the row count before and after every join, and I tell you what I checked.
What I write: joins across three or more tables, window functions, CTEs that break a long query into readable steps, aggregations that match your report, fixes for a query returning the wrong count, and rewrites for a query that is too slow.
PostgreSQL, MySQL, SQL Server, SQLite and BigQuery.
Ten years working with data that had to be right. Projects public at michaelnocito.github.io.
Database type:
Relational database
Platform:
BigQuery
•
MySQL
•
PostgreSQL
•
SQL Server
Expertise:
SQL
•
DQL
•
Performance
•
Query optimization
My Portfolio
FAQ
Do you need access to my database?
No, and I would rather not have it. Send your table and column names, or a CREATE TABLE script, or a small sample export. I write against that and you run it.
My query already runs. Can you check it is right?
Yes, and that is the order I like most. Send the query and what you expect it to return.
What if I do not know what my tables are called?
Send a screenshot of your schema, or export the first ten rows of each table. That is enough to work from.
Can you make a slow query faster?
Often. Send the query, and the EXPLAIN output if you can get it. I will tell you honestly if the fix is an index rather than a rewrite.
