This Git project is very helpful. I started from the same and did some changes as per my need. public sealed class DalSession : IDisposable { public DalSession() { _connection = new OleDbConnection(DalCommon.ConnectionString); _connection.Open(); _unitOfWork = new UnitOfWork(_connection); } IDbConnection _connection = null; UnitOfWork _unitOfWork = null; public UnitOfWork UnitOfWork { get { return _unitOfWork; … Read more
The best I was able to achieve was 50k records in 4 seconds using this approach SqlTransaction trans = connection.BeginTransaction(); connection.Execute(@” insert Member(Username, IsActive) values(@Username, @IsActive)”, members, transaction: trans); trans.Commit();
I’ve been using Dapper for a while now and have wondered what the Contrib and Rainbow projects were all about myself. After a bit of code review, here are my thoughts on their uses: Dapper.Contrib Contrib provides a set of extension methods on the IDbConnection interface for basic CRUD operations: Get Insert Update Delete The … Read more
There is now (n Dapper 1.26 and higher) direct support for table-valued parameters baked into dapper. In the case of stored procedures, since the data type is built into the sproc API, all you need to do is supply a DataTable: var data = connection.Query<SomeType>(…, new { id=123, name=”abc”, values = someTable }, …); For … Read more
There’s various ways already shown; personally I’d just use the non-generic api: var dict = conn.Query(sql, args).ToDictionary( row => (string)row.UniqueString, row => (int)row.Id);
You are doing nothing wrong, it is just not the way the API was designed. All the Query APIs will always return an object per database row. So, this works well on the many -> one direction, but less well for the one -> many multi-map. There are 2 issues here: If we introduce a … Read more
Try: term = “whateverterm”; var encodeForLike = term => term.Replace(“[“, “[[]”).Replace(“%”, “[%]”); string term = “%” + encodeForLike(term) + “%”; var data = conn.Query(@” select top 25 Term as Label, Type, ID from SearchTerms WHERE Term like @term”, new { term }); There is nothing special about like operators, you never want your params inside … Read more
This post shows how to query a highly normalised SQL database, and map the result into a set of highly nested C# POCO objects. Ingredients: 8 lines of C#. Some reasonably simple SQL that uses some joins. Two awesome libraries. The insight that allowed me to solve this problem is to separate the MicroORM from … Read more
QueryMultiple supports the ability to deal with multiple result sets. The only design restriction we added was totally disabling buffering for the grid reader. This means the whole API is streaming. In the simplest case you can use: var grid = connection.QueryMultiple(“select 1 select 2”); grid.Read<int>().First().IsEqualTo(1); grid.Read<int>().First().IsEqualTo(2); In the slightly more sophisticated case you can … Read more
Yes: var dbArgs = new DynamicParameters(); foreach(var pair in args) dbArgs.Add(pair.Key, pair.Value); Then pass dbArgs in place of args: var stuff = connection.Query<ExtractionRecord>(query, dbArgs); Alternatively, you can write your own class that implements IDynamicParameters. Note that if you are starting from an object (the usual approach with dapper), you can also use this template with … Read more