Articles

SQL Server Error 245: Conversion Failed from varchar to int

Diagnose SQL Server Msg 245 by finding invalid varchar values and implicit conversions, then choose a safe fix with TRY_CONVERT or matching types.

SQL Server Error 515: Cannot Insert NULL into a NOT NULL Column

Diagnose SQL Server Msg 515 by checking the named NOT NULL column, supplied values, omitted columns, and default constraints.

SQL Server Error 8115: Arithmetic Overflow

Diagnose SQL Server Msg 8115 from integer expressions, SUM, AVG, COUNT, and conversions; widen values before the operation.

SQL Server Error 8120: Column Is Not in GROUP BY

Fix SQL Server Msg 8120 by grouping every nonaggregate select expression, choosing a meaningful aggregate, or using a window function.

MySQL VALUES Statement: Create a Table of Rows

Use MySQL’s standalone VALUES statement as a table value constructor. Learn ROW syntax, default columns, aliases, ORDER BY, LIMIT, and how it differs from INSERT VALUES.

MySQL VALUES() Function in ON DUPLICATE KEY UPDATE

Learn what MySQL VALUES(column) returns in an upsert, why it is deprecated in 8.0.20+, and how to replace it with row and column aliases.

How to Size a MySQL Connection Pool

Calculate a safe MySQL pool ceiling across app replicas, then tune it with database and application metrics instead of guessing.

Enable the MySQL 26.7 Thread Pool on Debian 13

Enable and verify MySQL 26.7 Community Thread Pool on Debian 13, then inspect its Performance Schema tables and tune only after testing.

MySQL Error 2015: Named Pipe Connection on Windows

Troubleshoot MySQL Error 2015 on Windows by checking named-pipe support, the pipe name, and client access permissions.

Upgrade MySQL 9.7 LTS to 26.7 Innovation on Debian 13

Plan a Debian 13 upgrade from MySQL 9.7 LTS to 26.7 Innovation with Oracle’s APT repository, a verified backup, and package checks.