||Versions is container for Version objects. Version is version of data. At the beginning version is created as copy of existing table or is imported from CSV file.
When something modify data in this version then it can save modify data as new data version that is derived from the first version.
Container Versions offers this functionality for creating versions:
- VersionFromFile - for import from CSV file
- VersionFromTable - for import from existing table
- VersionFromTableToTable - for import from existing table to table with program specify properties (name, database connection, ...)
- VersionFromVersion - from add derived version
and other functinality:
- Add/Remove all created versions
- Fill up tree view control with tree of versions
Next important object is DataSrc object. This object can obtain using Version.GetTableInstance(bool readonly). If program want to read only data, then this copy are not copied into other temporary table. If program want to modify data then call GetTableInstance with false attribute. Data from this table will be copied into another.
DataSrc object offer useful methods for basic acces to data.
- Count of rows in table
- GetRow (reading data from table per rows)
- OdbcCommand for data manipulationg using SQL statements
- Version Id (from which version is)
- Freeze (copy data from this table into pemanent table using dialog Freeze - will not drop created table after dispose())
- contain object Table
Table object offers many mehods. We mention most important for data manipulating:
- Table.ColsInfo.SetTmpVals(object ) - set temporary values to insert into tables
- Table.InsertValues(OdbcCommand) - process insert SQL statements with temporary values