public TResult ExecuteScalar <TResult>(PreparedCommand preparedCommand)
{
using var command = CreateCommand(preparedCommand);
var result = command.ExecuteScalar();
if (result == DBNull.Value)
{
return(default);
public IEnumerable <TRecord> Stream <TRecord>(PreparedCommand command)
{
using var reader = ExecuteReader(command);
foreach (var item in ProcessReader <TRecord>(reader, command))
{
yield return(item);
}
}
public async IAsyncEnumerable <TRecord> StreamAsync <TRecord>(PreparedCommand command, [EnumeratorCancellation] CancellationToken cancellationToken = default)
{
await using var reader = await ExecuteReaderAsync(command, cancellationToken);
await foreach (var result in ProcessReaderAsync <TRecord>(reader, command, cancellationToken))
{
yield return(result);
}
}
public IEnumerable <TResult> Stream <TResult>(string query, CommandParameterValues args, Func <IProjectionMapper, TResult> projectionMapper, TimeSpan?commandTimeout = null)
{
var command = new PreparedCommand(query, args, RetriableOperation.Select, commandBehavior: CommandBehavior.Default, commandTimeout: commandTimeout);
using var reader = ExecuteReader(command);
var mapper = new ProjectionMapper(command, reader, configuration.ReaderStrategies);
while (reader.Read())
{
yield return(projectionMapper(mapper));
}
}
public async IAsyncEnumerable <TResult> StreamAsync <TResult>(string query, CommandParameterValues args, Func <IProjectionMapper, TResult> projectionMapper, TimeSpan?commandTimeout = null, [EnumeratorCancellation] CancellationToken cancellationToken = default)
{
var command = new PreparedCommand(query, args, RetriableOperation.Select, commandBehavior: CommandBehavior.Default, commandTimeout: commandTimeout);
await using var reader = await ExecuteReaderAsync(command, cancellationToken);
var mapper = new ProjectionMapper(command, reader, configuration.ReaderStrategies);
while (await reader.ReadAsync(cancellationToken))
{
yield return(projectionMapper(mapper));
}
}
IEnumerable <TRecord> ProcessReader <TRecord>(DbDataReader reader, PreparedCommand command)
{
using var timed = new TimedSection(ms => configuration.QueryLogger.ProcessReader(ms, name, command.Statement));
var strategy = configuration.ReaderStrategies.Resolve <TRecord>(command);
while (reader.Read())
{
var(instance, success) = strategy(reader);
if (success)
{
yield return(instance);
}
}
}
public async Task <int> ExecuteNonQueryAsync(PreparedCommand preparedCommand, CancellationToken cancellationToken = default)
{
using var command = CreateCommand(preparedCommand);
return(await command.ExecuteNonQueryAsync(cancellationToken));
}
public int ExecuteNonQuery(PreparedCommand preparedCommand)
{
using var command = CreateCommand(preparedCommand);
return(command.ExecuteNonQuery());
}
async IAsyncEnumerable <TRecord> ProcessReaderAsync <TRecord>(DbDataReader reader, PreparedCommand command, [EnumeratorCancellation] CancellationToken cancellationToken)
{
using var timed = new TimedSection(ms => configuration.QueryLogger.ProcessReader(ms, name, command.Statement));
var strategy = configuration.ReaderStrategies.Resolve <TRecord>(command);
while (await reader.ReadAsync(cancellationToken))
{
var(instance, success) = strategy(reader);
if (success)
{
yield return(instance);
}
}
}
public ProjectionMapper(PreparedCommand command, DbDataReader reader, IReaderStrategyRegistry readerStrategies)
{
this.command = command;
this.reader = reader;
this.readerStrategies = readerStrategies;
}
