public static async Task FastInsertAsync(this IDbConnection connection,
IEnumerable <object> list,
Type entityType,
Action <FastInsertConfig>?conf = null)
{
EnsureMySqlConnection(connection);
var config = GetConfig(conf, entityType);
if (!ConnectionStringValidator.ConnectionStringValid(connection.ConnectionString, out var error))
{
throw new ArgumentException(error);
}
var tableName = config.TableNameResolver.GetTableName();
var writer = CsvWriterConfigurator.GetWriter(entityType, config.BinaryFormat);
var tableDef = TypeInfoProvider.GetClassFields(entityType, config.BinaryFormat).ToList();
foreach (var partition in EnumerableExtensions.GetPartitions(list, config.BatchSize))
{
var fileName = $"{Guid.NewGuid()}.csv";
try
{
var csvSettings = new CsvFileSettings
(
delimiter: ";;",
lineEnding: Environment.NewLine,
path: fileName,
fieldEscapedByChar: "\\\\",
fieldEnclosedByChar: ""
);
var query = BuildLoadDataQuery.BuildQuery(tableName, tableDef, csvSettings);
await writer.WriteAsync(partition, csvSettings);
await connection.ExecuteAsync(query);
}
finally
{
if (config?.Writer != null)
{
await config.Writer.WriteLineAsync(fileName + ":");
await config.Writer.WriteLineAsync(File.ReadAllText(fileName));
}
File.Delete(fileName);
}
}
}
public static string BuildQuery(string tableName, List <Column> tableDef, CsvFileSettings settings)
{
var fieldsExpression = FieldsExpressionBuilder.ToExpression(tableDef);
var lines = new[]
{
$"LOAD DATA LOCAL INFILE '{settings.Path}'",
$"INTO TABLE {tableName}",
$"COLUMNS TERMINATED BY '{settings.Delimiter}' ENCLOSED BY '{settings.FieldEnclosedByChar}' ESCAPED BY '{settings.FieldEscapedByChar}'",
$"LINES TERMINATED BY '{settings.LineEnding}' STARTING BY ''",
$"IGNORE 1 LINES",
fieldsExpression
};
return(string.Join("\n", lines));
}
