/// <summary>
/// Takes a <see cref="IResolveFieldContext"/> and returns a hydrated object with the data.
/// </summary>
/// <param name="context">The <see cref="IResolveFieldContext"/>.</param>
/// <param name="databaseCall">A <see cref="DatabaseCallDelegate"/> that is passed the compiled SQL and calls the database and returns a <see cref="IDataReader"/>.</param>
/// <param name="cancellationToken">The <see cref="CancellationToken"/>.</param>
/// <returns>The correctly nested data from the database.</returns>
/// <exception cref="ArgumentNullException">If <c>context</c> or <c>databaseCall</c> is null.</exception>
public async Task <object?> ExecuteAsync(IResolveFieldContext context, DatabaseCallDelegate databaseCall,
CancellationToken cancellationToken)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (databaseCall == null)
{
throw new ArgumentNullException(nameof(databaseCall));
}
var sqlAst = _converter.Convert(context);
var sqlResult = _compiler.Compile(sqlAst, context);
var data = new List <Dictionary <string, object?> >();
using (var reader = await databaseCall(sqlResult.Sql, sqlResult.Parameters).ConfigureAwait(false))
{
while (await reader.ReadAsync(cancellationToken))
{
var item = new Dictionary <string, object?>();
for (var i = 0; i < reader.FieldCount; ++i)
{
var value = await reader.IsDBNullAsync(i, cancellationToken)
? null
: await reader.GetFieldValueAsync <object>(i, cancellationToken);
item[reader.GetName(i)] = value;
}
data.Add(item);
}
}
var objectShape = _objectShaper.DefineObjectShape(sqlAst);
#pragma warning disable 8620
var nested = _hydrator.Nest(data, objectShape);
var result = _arrayToConnectionConverter.Convert(nested, sqlAst, context);
#pragma warning restore 8620
if (result == null)
{
return(null);
}
await _batchPlanner.NextBatch(sqlAst, result, databaseCall, context, cancellationToken).ConfigureAwait(false);
return(result);
}
