JSON_CONTAINS checks whether a JSON document holds a value at a path, including inside an array. This post tests it on SQL Server 2025: the json data type it needs, numbers versus text, case, NULL results and the older OPENJSON way.
SQL SERVER – Script to Find First Day of Current Month
Michael Usov suggested a quick way to find the first day of current month while keeping the DATETIME datatype, with or without the time part.
First and Repeat Purchases: Tagging Customer Orders With ROW_NUMBER
Tag repeat purchases with deterministic order numbering, calculate days to the second order, and compare customer cohorts fairly.
MySQL – UDF – Validate Integer Function
MySQL has no ISNUMERIC function like SQL Server, so here is a simple user defined function that uses a regular expression to validate integer values.
Scalar UDF Inlining: When Old Functions Suddenly Get Fast
Check scalar UDF inlining eligibility, database settings, function options, and execution plans before claiming a performance improvement.
SELECT 7 & 7 or 7 ^ 7: Bitwise XOR, AND and OR on Integers
Understand bitwise XOR, AND and OR in T-SQL, test and change integer flags, explain two sevens, and compare the newer bit functions.
UNISTR and Unicode Escapes in SQL Server 2025
Build Unicode strings with UNISTR in SQL Server 2025, compare NCHAR, and preserve accented letters, Hindi text, and emoji in storage.