How-To Guides

Fixing Excel IFERROR That Hides Real Errors and Returns Wrong Results

IFERROR is supposed to be a safety net, but wrap it around the wrong formula and it silently swallows genuine mistakes while handing you bad data. Here's how to diagnose the problem and fix it properly.

Jun 28, 2026 9m read 👁 23

Fixing Excel VLOOKUP That Returns #N/A When Source Data Has Trailing Spaces

Your VLOOKUP formula looks perfect, the value is right there in the table, yet Excel still throws #N/A. Nine times out of ten, trailing spaces in your source data are the culprit — here's how to find and fix them fast.

Jun 28, 2026 8m read 👁 21

Fixing PostgreSQL CTE That Materializes When You Need It Inline

PostgreSQL 12 changed how CTEs are handled, and the difference between materialized and inlined CTEs can silently kill your query performance. Here's how to diagnose the problem and fix it with one keyword.

Jun 28, 2026 9m read 👁 27

Fixing Python xlsxwriter Hyperlinks That Break When Cell Text Exceeds 255 Characters

xlsxwriter silently drops or corrupts hyperlinks when the display text exceeds 255 characters. Learn exactly why this limit exists, how to detect it, and three practical workarounds you can ship today.

Jun 27, 2026 9m read 👁 18

Fixing Python xlsxwriter That Generates Duplicate Header Rows on Sheet Merge

Merging multiple sheets into one with xlsxwriter and ending up with headers sprinkled throughout your data? Here's exactly why that happens and how to write the merge loop that gets it right every time.

Jun 27, 2026 9m read 👁 18

Fixing Python xlsxwriter That Writes Datetime Values as Float Serial Numbers

Writing datetime objects with xlsxwriter and getting ugly floats like 45123.708333 instead of a readable date? Here's why it happens, what the format object actually does, and how to fix it for good.

Jun 27, 2026 8m read 👁 14

Fixing Python xlsxwriter That Skips Data Validation Rules on Protected Sheets

You set up data validation dropdowns in xlsxwriter, added sheet protection, opened the file in Excel — and the dropdowns are gone. Here's exactly why that happens and how to fix it without losing your protection settings.

Jun 27, 2026 8m read 👁 16

Fixing Python xlsxwriter That Ignores freeze_panes When Workbook Has Multiple Sheets

You've called freeze_panes on every sheet, but when the file opens in Excel only some sheets are frozen—or none at all. Here's exactly why xlsxwriter silently drops the setting and how to fix it for good.

Jun 26, 2026 9m read 👁 12

Fixing Python xlsxwriter That Loses Named Ranges After Workbook Close

You define named ranges in xlsxwriter, open the file in Excel, and they're gone. This happens because of a subtle sequencing and scope issue — here's exactly how to fix it and verify your ranges persist.

Jun 26, 2026 7m read 👁 11

Fixing PostgreSQL EXPLAIN ANALYZE That Shows Seq Scan Despite an Index

You added an index, ran your query, and EXPLAIN ANALYZE still shows a sequential scan. Before you blame PostgreSQL, there are at least six specific reasons this happens — and each one has a clear fix.

Jun 25, 2026 10m read 👁 25

Fixing Python xlsxwriter That Applies Wrong Row Height After autofit

xlsxwriter's autofit method sets row heights that look right in the preview but end up clipped or oversized in Excel. Here's why it happens and exactly how to calculate correct row heights yourself.

Jun 25, 2026 9m read 👁 23

Fixing PostgreSQL Foreign Key Constraint That Silently Fails on Bulk Insert

Bulk-inserting rows into PostgreSQL and watching foreign key violations disappear without an error? This guide explains exactly why that happens and how to force PostgreSQL to catch every violation reliably.

Jun 25, 2026 10m read 👁 11