T-SQL mistakes, in the two-panel format the children’s magazines used. Careless writes it one way. Careful writes it the other. Every pair was run on the same 1,200,000 rows on SQL Server 2025 and measured. One pair returned a wrong answer. One I stopped after fourteen minutes of CPU.
Nine Unusual Ways My Clients Use AI With SQL Server
Everyone writes about AI generating queries. Here are nine unusual ways my clients use AI with SQL Server, and I helped build every one.
EXISTS vs IN vs JOIN: Writing Semi-Joins
Compare EXISTS, IN, and JOIN for semi-joins, prevent duplicate customer rows, and handle NULL safely in exclusion queries.
SQL SERVER – Unique Indexes on Nullable Columns
As the server allows only one null value in a column if a unique constraint is applied. Let us learn about Unique Indexes on Nullable Columns.
SQL SERVER – Difference Between ISNULL and COALESCE
SQL Server provides two commonly used functions, ISNULL and COALESCE, to address this requirement. Difference Between ISNULL and COALESCE
IGNORE NULLS in SQL Server 2022: Carrying the Last Known Value Forward
Use IGNORE NULLS for forward-filled readings, find the next known value, and compare the older running-count grouping method carefully.
A Unique Constraint That Allows Many NULLs
Allow many NULLs while enforcing unique non-NULL values with a filtered SQL Server index, required SET options, and tested queries.