Entity Framework: “Store update, insert, or delete statement affected an unexpected number of rows (0).” [closed]

Answer 1

I came across this issue on a table that was missing a primary key and had a DATETIME(2, 3) column (so the entity's "primary key" was a combination of all the columns)... When performing the insert the timestamp had a more precise time (2018-03-20 08:29:51.8319154) that was truncated to (2018-03-20 08:29:51.832) so the lookup on key fields fails.