代码我复制如下
using (var db = new MyDBContext())
{
db.Database.ExecuteSqlCommand($"DELETE ARoleGroupDetail WHERE GId= {gid}");
List<int> roles = GetTreeViewNodeChecked(treeView1);
GlobalCache.UseRoleList = GlobalCache.TableList.Where(x => roles.Contains(x.Id)).ToList();
if (roles.Count > 0)
{
foreach (var id in roles)
{
db.ARoleGroupDetails.Add(new ARoleGroupDetail()
{
GId = gid,
RId = id
});
}
db.SaveChanges();
}
我不明白 $"DELETE ARoleGroupDetail WHERE GId= {gid}" 前面为什么有一个美元符号,是什么作用呢