DapperLib / DapperLib/Dapper

Support TVP directly InList as IEnumerable

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Description

Hi,

I have a branch here https://github.com/osexpert/Dapper/tree/TVPParameters
I have added support for TVP directly as argument.

Example:

SqlMapper.Settings.InListTVPCount = 1;

var list = new List<int>();
list.Add(42);
// Add some extras, to see that it works with many arguments:
for (int i = 100; i < 100000; i++)
	list.Add(i);

var res = conn.Query("select * from persons where id in @ids", new { ids = list });

The table types must currently be created outside of Dapper.
A few types are handled by default (byte, short, int, long, Guid).
Other types can be added, eg:
SqlMapper.Settings.InListTVPHandlers.Add(typeof(DateOnly), new() { IdColumn = "Id", TypeName = "Dapper_DateOnly" });

And create the type is ms sql:
CREATE TYPE dbo.Dapper_DateOnly AS TABLE (Id date NOT NULL)

There is no tests written yet, but I will write some if this is something that can be merged.
It is also possible to add a way to get the table types created. Must still be done manually, but then at least can call a method in Dapper to create them (or get the sql for them) instead of doing this all manually.

Thanks.

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Review the TVPParameters branch and the SqlMapper.Settings.InListTVPCount and InListTVPHandlers entry points first. Add tests for the IEnumerable example, the built-in types, and a custom handler, then verify the SQL Server table-type requirements and define whether table-type creation is in scope.

Written by the indexing model from the issue text.

Assessment

Tech stack
csharp, sql
Domain
database
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
38/100

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