Class Row (2.34.0-rc)

The Row class is a regular value type that may be copied, moved, assigned, compared for equality, etc. Instances may be large if they hold lots of Value data, so copy only when necessary.

Row instances are typically returned as the result of queries or reads of a Cloud Spanner table (see Client::Read and Client::ExecuteQuery). Users will mostly just use the accessor methods on Row, and will rarely (if ever) need to construct aRow` of their own.

The number of columns in a Row can be obtained from the size() member function. The Values can be obtained using the values() accessor. The names of each column in the row can be obtained using the columns() accessor.

Perhaps the most convenient way to access the Values in a row is through the variety of "get" accessors. A user may access a column's Value by calling get with a std::size_t 0-indexed position, or a std::string column name. Furthermore, callers may directly extract the native C++ type by specifying the C++ type along with the column's position or name.

Example

Row row = ...;
if (StatusOr<std::string> x = row.get<std::string>("LastName")) {
  std::cout << "LastName=" << *x << "\n";
}