Multi-database access layer for Codeer.LowCode.Blazor server applications.

Provides the standard IDbAccessor implementation (DbAccessor) used by the server side of a Codeer.LowCode.Blazor application. It supports SQL Server / PostgreSQL / Oracle / SQLite / MySQL with a single API, using Dapper for parameter binding and a common row-materialization path.

• NuGet: Codeer.LowCode.Blazor.DbAccess
• License: MIT (this project). See the note below about bundled database providers.

Reference the package from your server project and register DbAccessor as the IDbAccessor (exactly as the application templates do):

using Codeer.LowCode.Blazor.DbAccess;

IDbAccessor accessor = new DbAccessor(dataSources);

Every member of DbAccessor is virtual, so you can subclass it to insert logging, retries, or provider-specific value binding without forking the code:

public class MyDbAccessor : DbAccessor
{
    public MyDbAccessor(DataSource[] dataSources) : base(dataSources) { }

    public override async Task<List<IDictionary<string, object>>> QueryAsync(
        string dataSourceName, string query, Dictionary<string, ParamAndRawDbTypeName> args)
    {
        // ... custom logging / retry ...
        return await base.QueryAsync(dataSourceName, query, args);
    }
}

If you prefer not to take a dependency on this package, copy the source from this repository into your own project and modify it as needed.

Since the package source cannot be stepped into while debugging, DbAccessor provides a debug log mode instead. Assign a sink to the static DbAccessor.SqlLog property and every execution (QueryAsync / ExecuteAsync / InsertAsync / ExecuteSqlCommandAsync) dumps the SQL and its parameters — including output parameter values after execution. It is null by default (disabled, no overhead).

// e.g. in Program.cs, for development only
DbAccessor.SqlLog = Console.WriteLine;
// or route to your logger
DbAccessor.SqlLog = message => logger.LogDebug(message);

Example output:

[SQL] Query (Main)
--------------------------------------------------
SELECT * FROM t WHERE id = @id
--------------------------------------------------
id = 123 (Int32)

[SQL] ExecuteSqlCommand NonQuery (Main)
--------------------------------------------------
BEGIN PROC_PARAM_TEST(:num_in, :num_out); END;
--------------------------------------------------
num_in = 111 (Decimal) (Input, Decimal)
num_out = null (Output, Decimal)

[SQL] ExecuteSqlCommand result (Main)
ReturnValue = -1 (Int32)
num_out = 1110 (OracleDecimal)

Note: parameter values may contain sensitive data — enable this only in development environments.

This package declares (but does not redistribute) the following database providers. Each is restored by NuGet on the consumer side:

All are free for commercial use. Only the Oracle provider is under a proprietary (though free) license rather than an OSI-approved open-source license; review the Oracle FUTC if that matters to you.