Subquery Returns Multiple Rows In Comparison?!
Using subquery that returns multiple rows in = comparison crashes! SQL doesn't know which row to use. This breaks subqueries! Watch!
#sql #sqltricks #database #sqltutorial #subqueries #multiplerows #sqlquiz #codingchallenge #sqlshorts #sqlbugs #subqueryerrors #sqlwtf
JSON Column Search Takes 47 SECONDS Breaking Black Friday?!
JSON SEARCH NIGHTMARE! Can't index JSON columns in older MySQL! Every product search scans 2 MILLION rows! 47-second queries! Server MELTS on Black Friday! $4.7M revenue LOST! Watch the horror!
#sql #sqldisaster #json #performance #noindex #slowquery #sqlfails #blackfriday #sqlshorts #databasedisaster #sqlwtf #jsonsearch
DELETE Without WHERE Deletes EVERYTHING?!
STOP RIGHT NOW! Forgot WHERE clause in DELETE? Your ENTIRE table is GONE! 10 million users DELETED in production! This is every developer's NIGHTMARE! Watch this disaster!
#sql #sqldisaster #delete #productionbug #sqlfails #codingnightmare #sqlshorts #databasedisaster #careerendingbug #sqlwtf #deletewithoutwhere #dataloss
0.1 + 0.2 In SQL = 0.30000000000000004?!
SQL floating point precision is broken! Adding 0.1 + 0.2 creates a number with precision errors. This breaks financial calculations! Watch!
#sql #sqltricks #database #sqltutorial #floatingpoint #precision #sqlquiz #codingchallenge #sqlshorts #sqlbugs #numericprecision #sqlwtf
HAVING Filters After GROUP BY?!
HAVING filters GROUPS, WHERE filters ROWS! HAVING runs after aggregation, WHERE runs before. This order matters and will break your logic!
#sql #sqltricks #having #where #groupby #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #aggregation #advancedsql
Window ORDER BY NULLS FIRST - LAST?!
NULLS FIRST and NULLS LAST change window function results! The order of NULLs matters in window functions. This subtle difference will cause bugs!
#sql #sqltricks #windowfunctions #nullsfirst #nullslast #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #nullhandling #advancedsql
Decimal Precision Rounds Numbers?!
DECIMAL precision ROUNDS values! Cast 1.999 to DECIMAL(5,2) and it becomes 2.00. This silent rounding will cause calculation errors!
#sql #sqltricks #decimal #precision #rounding #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #datatypes #advancedsql
COUNT(*) vs COUNT(column) Are DIFFERENT?!
COUNT(*) and COUNT(column) behave completely differently with NULLs! One counts NULLs, one doesn't. This breaks aggregate logic! Watch!
#sql #sqltricks #database #sqltutorial #count #aggregate #sqlquiz #codingchallenge #sqlshorts #sqlbugs #nullhandling #sqlwtf
JOIN With NULL Keys Returns ZERO Rows?!
JOINing tables with NULL keys returns ZERO rows! NULL = NULL in JOIN is FALSE. This breaks all join logic! Watch!
#sql #sqltricks #database #sqltutorial #join #nullkeys #sqlquiz #codingchallenge #sqlshorts #sqlbugs #joins #sqlwtf
ROW_NUMBER() OVER (ORDER BY NULL) Does WHAT?!
ROW_NUMBER with ORDER BY NULL creates non-deterministic ordering! All rows get random numbers. This breaks window functions! Watch!
#sql #sqltricks #database #sqltutorial #rownumber #windowfunctions #sqlquiz #codingchallenge #sqlshorts #sqlbugs #ordering #sqlwtf
PrecisionSQL