SQL "Ambiguous Column Name": Causes and Fixes
By Sharon Ben-Moshe · Jul 13, 2026
A SQL "ambiguous column name" error means a JOIN produced same-named columns and your query didn't say which one it meant. Here's the fix, dialect by dialect.
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SQL Errors.
Explanations and fixes for common SQL error messages across PostgreSQL, MySQL, SQLite, SQL Server, and BigQuery.
9 posts
Fix "column must appear in the GROUP BY clause"
By Sharon Ben-Moshe · Jun 25, 2026
PostgreSQL's "column must appear in the GROUP BY clause" error (42803) fires when a SELECT column isn't grouped or aggregated. Three fixes, with examples.
Read postHow to Fix BigQuery Syntax Errors
By Sharon Ben-Moshe · Jun 15, 2026
BigQuery syntax errors point past the real mistake. Here are 7 common causes—wrong clause order, reserved words, Legacy SQL—with runnable fixes.
Read postCommon SQL Keyword Typos and How to Catch Them
By Sharon Ben-Moshe · Jun 14, 2026
SELEC, FORM, WHER — SQL keyword typos produce confusing parser errors. Here are the most common SQL misspellings and the fastest ways to catch them.
Read postHow to Fix "Incorrect Syntax Near" in SQL Server
By Sharon Ben-Moshe · Jun 14, 2026
SQL Server's "Incorrect syntax near" error means the T-SQL parser hit an unexpected token. Here are 7 common causes and how to fix each one.
Read postHow to Fix 'near X: syntax error' in SQLite
By Sharon Ben-Moshe · Jun 14, 2026
SQLite's 'near X: syntax error' points just past the real mistake. Here are 7 common causes—reserved words, quote confusion, version gaps—with fixes.
Read postSQL NULL Comparison: Why = NULL Never Works
By Sharon Ben-Moshe · Jun 14, 2026
SQL's = NULL comparison always returns unknown, never true. Learn why NULL requires IS NULL, how three-valued logic works, and how to fix common NULL bugs.
Read postFix "You Have an Error in Your SQL Syntax" (MySQL)
By Sharon Ben-Moshe · Jun 13, 2026
"You have an error in your SQL syntax" (MySQL error 1064) means the parser hit an unexpected token. Here are the 7 common causes and how to fix each.
Read postHow to Fix "syntax error at or near" in PostgreSQL
By Sharon Ben-Moshe · Jun 12, 2026
PostgreSQL's "syntax error at or near" means the parser hit a token it can't place — usually just after the real mistake. The six causes, with fixes.
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