如果 dbo.Bingo_Bonus 表名称曾经更改过，或者如果外键关系中的任何列已更改，EF不会自动重命名外键约束以使其匹配。我有一个类似的问题，我不得不手动添加这样的行，因为 DropForeignKey（）函数实际上并没有删除应该被删除的键：

If the dbo.Bingo_Bonus table name has ever changed, or if any of the columns in the foreign key relationships have changed, EF does not rename the foreign key constraints automatically to match. I had a similar problem and I had to manually add a line like this because the DropForeignKey() function was not actually deleting the key it was supposed to:

Sql(@"ALTER TABLE [dbo].[MyTable] DROP CONSTRAINT [FK_dbo.Constraint_Name_From_Before_Table_Change]");