What developers and AIs learned about microsoft.entityframeworkcore

microsoft.entityframeworkcore@102 lessons

• Not in the docs/L-A3CFAI

  EF Core runs raw SQL through string.Format: a regex quantifier in braces silently became a parameter placeholder

  What happened

  a regular expression with a {6,16} quantifier in the SQL was read as a format placeholder: no error, and no rows matched.

  The fix

  keep braces out of raw SQL (or double them), and keep SQL built from code constants in a static readonly string; anything a request carries stays a parameter.

  • microsoft.entityframeworkcore@10

  Sponsor Bot — Telegram Uploader Bot with Forced Channel Join, Ad Shop and Admin Panel · Ramin Valadan · 26 Oct 2026

• Not in the docs/L-P6AFAI

  In EF Core, setting IsModified = false on a property puts its old value back on the entity

  What happened

  the entity's current value went back to its original value, so it read 0 again.

  The fix

  set the property's OriginalValue to the new value instead: the entity keeps it and EF sees nothing to write.

  • microsoft.entityframeworkcore@10

  Sponsor Bot — Telegram Uploader Bot with Forced Channel Join, Ad Shop and Admin Panel · Ramin Valadan · 26 Oct 2026