System.Data — H2Sharp

System.Data / ADO.NET available

A standard ADO.NET provider in H2Sharp.Data (System.Data.Common). It is measured against the inherited AdoNet.Specification.Tests conformance suite and by a green Dapper flow — not against itself.

In-memory today. The provider opens mem: databases. File databases and async OpenAsync are not ported yet — the MVStore layer itself is file-compatible both ways, but the provider does not open files at this point.

Gate (phase 8) — closed twice over: DapperSmokeTests drives an in-memory database end to end over IDbConnection (open → create → insert → update → select → delete), and the inherited AdoNet.Specification.Tests suite is 293 of 293 green. Source: src/H2Sharp/Data/, tests: tests/H2Sharp.Data.Tests/.

Types

Type	Base	Notes
`H2Connection`	`DbConnection`	Also exposes `CurrentDatabase` (the engine's `Database`) for engine-level work.
`H2Command`	`DbCommand`	`ExecuteNonQuery`, `ExecuteScalar`, `ExecuteReader`, their `Async` forms, `Prepare`, `Cancel`, `Parameters`.
`H2Parameter`	`DbParameter`	Parameters travel beside the text — they are never concatenated into it.
`H2DataReader`	`DbDataReader`	Full typed getter set, `GetBytes`/`GetChars`, `GetSchemaTable`.
`H2Transaction`	`DbTransaction`	Works. Wraps an engine `Tx.Transaction`: `Commit`, `Rollback`, `IsolationLevel`. Statements commit at the reference's points, so a single DML statement is durable on its own and auto-commit is fixed.
`H2DataAdapter`	`DbDataAdapter`	Fill / update from a select command, for `DataSet`-style code.
`H2CommandBuilder`	`DbCommandBuilder`	Builds insert / update / delete commands for a table.
`H2ConnectionStringBuilder`	`DbConnectionStringBuilder`	`DataSource`, `UserId`, `Password`, `ToH2ConnectionString()`.
`H2ProviderFactory`	`DbProviderFactory`	Entry point for DI and tooling: `H2ProviderFactory.Instance`.

Connection strings

Both spellings are accepted, because a caller will use whichever their code base already has. The jdbc:h2: prefix is stripped and not re-added, so Data Source=mem:x and Data Source=jdbc:h2:mem:x open the same database — the name itself is kept byte for byte, because the name decides which database is opened.

Data Source=mem:mydb                       // ADO.NET spelling
Data Source=jdbc:h2:mem:mydb              // H2 spelling, same database

new H2ConnectionStringBuilder("jdbc:h2:mem:mydb").ToH2ConnectionString()

Registration

services.AddDbConnectionFactory<H2ProviderFactory>(_ => new H2ProviderFactory());
// or construct directly:
await using var con = new H2Connection("jdbc:h2:mem:mydb");

Transactions

using var tx = con.BeginTransaction();
con.Execute("INSERT INTO PERSON VALUES(@Id, @Name)", new { Id = 2, Name = "Grace" });
tx.Commit();  // or tx.Rollback()

Not implemented yet

Honest list — these throw TODOException or are absent, by design at this stage:

ChangeDatabase — throws TODOException.
Connection-level GetSchema() over INFORMATION_SCHEMA — not there yet. (H2DataReader.GetSchemaTable() is a different thing and does work.)
File databases and async OpenAsync.
No batches — CanCreateBatch is false.
No data-source enumerator — CanCreateDataSourceEnumerator is false.
File databases and async OpenAsync.

See also Dapper for the live end-to-end flow, and port status for phases.