Fixing the "String or Binary Data Would Be Truncated" Error in EF Core

Fixing the "String or Binary Data Would Be Truncated" Error in EF Core If you’ve worked with Entity Framework Core and SQL Server, you’ve likely encountered this error: String or binary data would be truncated At first glance, this error is frustrating because it doesn't tell you: Which table failed Which column caused the issue What the allowed size is What value exceeded the limit So debugging becomes time-consuming. The Problem Consider this table: Users FirstName VARCHAR(20) Now insert: "ThisIsAVeryLongNameThatExceedsLimit" SQL Server throws: String or binary data would be truncated But gives no details. The Solution: DBGuard To solve this, I built a library called DBGuard. DBGuard validates entity data against the actual database schema before SaveChanges. How It Works Flow: Application → EF Core SaveChanges → DBGuard Interceptor → Validation Engine → Database Example Instead of SQL Server error: String or binary data would be truncated DBGuard returns: DBGuard Validation Failed T