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Step-by-step articles on MCP servers, AI + database integrations, and more. — Page 4
Why Your AI's Percentage Calculation Comes Back as 0
Asked for a conversion rate or percentage and got 0% back for something you know isn't zero. In Postgres and SQL Server, dividing an integer by an integer truncates to a whole number — 3 divided by 10 is 0, not 0.3. MySQL doesn't have this problem, which makes it worse to debug.
August 29, 2026
Why Your AI's LEFT JOIN Quietly Becomes an INNER JOIN
Asked for 'all customers and their orders, including customers with none' — got back only customers who have orders. A LEFT JOIN with a filter on the right-hand table sitting in WHERE instead of ON silently defeats the whole point of the LEFT JOIN.
August 29, 2026
Why Your AI's Date Range Query Misses the Last Day
Asked for 'orders in August' and August 31st is missing, even though rows clearly exist for that day. BETWEEN '2026-08-01' AND '2026-08-31' on a timestamp column means up to midnight on the 31st — not through the end of the day.
August 26, 2026
Why Your AI's Boolean Filter Fails Across Databases
WHERE is_active = true works in Postgres and throws a syntax error in SQL Server, where the same column is really a BIT and needs = 1. MySQL's BOOLEAN is secretly a TINYINT too. Why 'true' and 'false' aren't universal SQL, and what to ask for instead.
August 26, 2026
Why Your AI's Search Misses Rows That Clearly Match
Asked for customers with status 'Active' and it missed rows spelled 'active'. Whether that filter matches depends on which database you're connected to — Postgres string comparison is case-sensitive by default, MySQL usually isn't, SQL Server depends on collation.
August 26, 2026
Why Your AI's Filter Silently Skips Rows With NULL Values
Asked for 'customers without a plan assigned' or 'orders that aren't cancelled' and got back fewer rows than you know exist. NULL doesn't behave like a normal value in SQL comparisons — != and NOT IN both silently drop rows they should include.
August 20, 2026
Why Your AI's SUM Comes Back NULL Instead of Zero
Asked for total revenue for a plan with no sales this month and got back NULL, or a follow-up calculation that turned every number into nothing. SUM (and AVG, MAX, MIN) return NULL when there are zero matching rows — not zero — and that NULL poisons anything built on top of it.
August 20, 2026
Why Your AI Gets a Different Answer to the Same Database Question
Asked the same question twice and got two different lists of 'top 10 customers' or 'recent signups' — with the same data, same filters, no error. Usually a LIMIT with no ORDER BY, which Postgres and MySQL don't guarantee stays consistent.
August 19, 2026
Why Your AI Database Tool Says 'Too Many Connections'
Your AI database connector worked fine, then started failing with 'too many connections' or 'remaining connection slots are reserved' — especially on Supabase or Neon. What's actually happening, and why the fix is usually the pooler endpoint, not a bigger plan.
August 19, 2026
Why Your AI's Numbers Are Too High: The JOIN Fan-Out Problem
The query ran fine, no errors, and the total revenue or order count came back way higher than you know it should be. Almost always a JOIN multiplying rows before the SUM or COUNT runs — here's how to spot it and how to ask AI to avoid it.
August 19, 2026