Insert error about multithreading

[ellenfier]

Insert error about multithreading

[valfrid-ly]

Except for changing

AllColumns = GetColumns().ToList();
AllColumns = AllColumns.Select(c => new ColumnAllColumns = GetColumns().Select(c => new Column

for

AllColumns = GetColumns().Select(c => new Column

I see no difference in your code that justifies any change in the key

[ellenfier]

Well, I use a local variable 'allColumns' instead of AllColumns and a ConcurrentDictionary to keep the columns value.

var allColumns = GetColumns().Select(c => new Column()).ToList(); // or _dictionary[classMapper]
//AllColumns = GetColumns().ToList();
//******
AllColumns = allColumns;

The method 'DapperImplementor.GetSimpleAliasFromColumnAlias(string columnAlias)' will return the value of SimpleAlias. And if it is null or empty, the key of DynamicParameter will be the PropertyInfo.Name instead of SimpleAlias.
When the method GetSimpleAliasFromColumnAlias is invoked by a thread, and at the same time AllColumns = GetColumns().ToList() is invoked by another thread, the problem happens. It's now thread safe.

I also change the method GetSimpleAliasFromColumnAlias.
like
SqlGenerator.GetColumnsByClassMapper(prop.ClassMapper).Any(c => c.Alias.Equals....

[valfrid-ly]

Would you be able to send a PR with your changes??

Please, don't forget to update the unit tests too.