@Nullable open fun mapRow(rs: ResultSet, rowNum: Int): T
Extract a value for the single column in the current row.
Validates that there is only one column selected, then delegates to getColumnValue() and also convertValueToRequiredType, if necessary.
See Also
java.sql.ResultSetMetaData#getColumnCount()#getColumnValue(java.sql.ResultSet, int, Class)#convertValueToRequiredType(Object, Class)