private ParameterContext GetParameterContext(ParameterContext parameterContext, List <string> parameterNames) { if (0 == _parametersCount) { return(new ParameterContext(0)); } var result = new ParameterContext(_parametersCount); foreach (var parameterName in parameterNames) { if (!parameterContext.TryGetDbParameter(parameterName, out var dbParameter)) { throw new ShardingException($"parameter name:[{parameterName}] not found in parameters"); } result.AddParameter(dbParameter); } return(result); }