sqlfmt▍
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Explanations and fixes for common SQL error messages across PostgreSQL, MySQL, SQLite, SQL Server, and BigQuery.
31 posts
By Sharon Ben-Moshe · Sep 29, 2026
Fix Google BigQuery's "Unrecognized name: column" error. Learn alias visibility rules across WHERE and QUALIFY, case sensitivity, and struct unnesting.
Read postBy Sharon Ben-Moshe · Sep 26, 2026
Understand SQLite Error 20 (datatype mismatch). Learn how SQLite type affinity, CHECK constraints, and STRICT tables enforce data integrity.
Read postBy Sharon Ben-Moshe · Sep 23, 2026
Fix PostgreSQL Error 57014: canceling statement due to statement_timeout. Learn how to tune query plans, configure timeouts per session, and avoid lock waits.
Read postBy Sharon Ben-Moshe · Sep 20, 2026
Fix SQL Server Error 8152 and 2628: String or binary data would be truncated. Discover how to identify the offending column and increase column size.
Read postBy Sharon Ben-Moshe · Sep 17, 2026
Troubleshoot MySQL Error 1064 (You have an error in your SQL syntax). Learn how to identify unquoted reserved words, hanging commas, and quote issues.
Read postBy Sharon Ben-Moshe · Sep 14, 2026
Diagnose and resolve PostgreSQL Error 40P01 (deadlock detected). Learn how to order resource locks, shorten transaction windows, and tune deadlock_timeout.
Read postBy Sharon Ben-Moshe · Sep 11, 2026
How to resolve SQL Server Msg 512 and PostgreSQL 21000: Subquery returned more than 1 value. Replace scalar subqueries with JOINs, IN, or TOP 1.
Read postBy Sharon Ben-Moshe · Sep 8, 2026
Resolve MySQL Error 1215 and 1452. Discover how to fix column type mismatches, collation differences, missing parent indexes, and orphan records.
Read postBy Sharon Ben-Moshe · Sep 5, 2026
Troubleshoot and fix PostgreSQL Error 23505: duplicate key value violates unique constraint. Learn how to fix desynced sequences and use ON CONFLICT.
Read postBy Sharon Ben-Moshe · Sep 2, 2026
Learn how to prevent and fix division by zero errors in SQL using NULLIF, CASE expressions, and database-specific safe division functions.
Read postBy Sharon Ben-Moshe · Aug 26, 2026
Fix PostgreSQL error 42P01 by checking the database, schema search path, exact identifier case, migrations, and object permissions.
Read postBy Sharon Ben-Moshe · Aug 26, 2026
Fix MySQL ERROR 1054 (42S22) by checking table columns, aliases, clause visibility, identifier quoting, and the migration actually deployed.
Read postBy Sharon Ben-Moshe · Aug 26, 2026
Fix SQL Server Msg 208, “Invalid object name,” by checking database context, schema qualification, metadata visibility, temporary-table scope, and collation.
Read postBy Sharon Ben-Moshe · Aug 26, 2026
Fix SQLite “database is locked” (SQLITE_BUSY) by finding long write transactions, setting a busy timeout, using WAL deliberately, and avoiding unsafe file access.
Read postBy Sharon Ben-Moshe · Aug 16, 2026
Learn to read PostgreSQL EXPLAIN ANALYZE: estimated versus actual rows, scan types, safe use with writes, and a repeatable tuning workflow.
Read postBy Sharon Ben-Moshe · Aug 8, 2026
MySQL's Error 1146 (“Table '...' doesn't exist”) almost always comes down to a missing database prefix, a case mismatch on a case-sensitive filesystem, or a table that never actually got created. Here's how to tell which.
Read postBy Sharon Ben-Moshe · Aug 8, 2026
PostgreSQL's “column X does not exist” error is one of its most literal messages — but it still trips people up over case folding, table aliases, and columns that exist on a different table than the one being queried.
Read postBy Sharon Ben-Moshe · Aug 8, 2026
SQL Server's “Conversion failed when converting the varchar value … to data type int” (Msg 245) means a string in your data, or your query, doesn't actually look like the number or date you're trying to convert it to.
Read postBy Sharon Ben-Moshe · Aug 2, 2026
SQLite's "no such table" error almost never means real data loss — it usually points to the wrong database file, an uncommitted transaction, or a missing ATTACH prefix. Here's how to diagnose it.
Read postBy Sharon Ben-Moshe · Aug 2, 2026
SQL Server's Msg 208, "Invalid object name," covers six distinct causes — from schema mismatches to temp tables that fell out of scope. Here's how to tell them apart and fix each one.
Read postBy Sharon Ben-Moshe · Aug 2, 2026
MySQL error 1054, "Unknown column 'x' in ...", covers five distinct causes — from simple typos to referencing a SELECT alias too early. Here's how to tell them apart.
Read postBy Sharon Ben-Moshe · Aug 2, 2026
PostgreSQL's "relation does not exist" error almost always traces back to one of six causes — from case folding to a stale search_path. Here's how to diagnose and fix each one.
Read postBy 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.
Read postBy 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 postBy 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 postBy 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 postBy 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 postBy 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 postBy 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 postBy 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 postBy 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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