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Fiverr Pro
English
$
USD
I will write, fix and optimize sql queries for postgresql, mysql or bigquery
About this Gig
Need a query that actually returns the right numbers? I write and fix SQL for analytics and reporting.
What I do
- New queries from a plain-English question ("monthly revenue by channel with MoM growth")
- Fix queries that are slow, return duplicates or give wrong totals (the usual cause is join fan-out)
- Window functions, CTEs, cohorts, retention, funnels, running totals, top-N per group
- Query tuning: rewrites, index suggestions, EXPLAIN review
- Converting queries between PostgreSQL, MySQL, SQLite, SQL Server, BigQuery and Snowflake
Every query comes with comments explaining the logic and a sample of its output from your data or a test copy. You won't receive anything I haven't run.
How I work: I use AI-assisted tools for drafting and documentation. I test, verify and take responsibility for every query myself.
I never need write access to production. A read-only user or a sample dump is enough.
Database type:
Relational database
Platform:
BigQuery
•
MySQL
•
PostgreSQL
•
SQLite
Expertise:
SQL
•
DQL
•
Performance
•
Query optimization
My Portfolio
FAQ
Which databases?
PostgreSQL, MySQL/MariaDB, SQLite, SQL Server, BigQuery, Snowflake and DuckDB.
Do you need database access?
Not necessarily. A schema (CREATE TABLE statements) plus a small sample is enough. If you share access, read-only only.
Can you explain the query so I learn?
Yes. Every query is commented, and Standard and Premium include a short walkthrough document.
Is this for homework or exams?
No. I help with work and learning projects, not graded assignments or live tests.
What if the result looks wrong?
Tell me which numbers you expected. Revisions are included, and I reconcile totals against your source.
