See Extended Table.

We call base table any table from the database where we are positioned at a certain time, for example, for retrieving or modifying its data.

When we execute a transaction with a single level, it has one associated base table that is: a physical table where the insertions, modifications and deletions that we operate – like for example interactively through the transaction screen – take place. 

When we work with a transaction with more than one level, each level has an associated base table where the insertions, modifications and deletions that we process through that level take place.

Also, when we define queries (a listing, for instance), we will be navigating a specific base table.

So, the base table is then any physical table in the database where we are positioned and working at a certain time.

Some examples:

  • For each command: the base table of a For Each is the physical table navigated, as determined by GeneXus. Even though a For Each doesn’t navigate only one physical table, but also an Extended Table, we say the For each has a base table that is navigated, and its extended table is accessed to retrieve or update data (or filter by an attribute that belong to the extended table, etc.).
     
  • New: Every time GeneXus finds a “new” command, it must identify the table where the record will be inserted. The table identified to make the insertion in it, is the base table in this case.
     
  • Data Provider: the base table of a Data Provider is the physical table navigated in order to charge a collection, or an instance in memory, etc. Even though a Data Provider doesn’t navigate only one physical table, but also an Extended Table, we say the Data Provider has a base table that is navigated and its extended table is accessed (for the purpose of retrieving data or filtering by an attribute that belong to the extended table, etc.).
     
  • Grid: the base table of a grid is the physical table navigated, in order to retrieve and display in the grid the required attributes. Even though not only one physical table is browsed, but also an Extended Table, we say the grid has a base table that is navigated, and its extended table is accessed (for the purpose of retrieving data too, or filtering  by an attribute that belong to the extended table, etc.).   
     
  • Formula: the base table of a formula is the physical table that is going to be navigated in order to evaluate it (to calculate its result value). 
     
  • Subtype Group object: the base table of a subtype group is the physical table whose complete primary key is included in the subtype group definition, as the key of the group (the subtype group must include a subtype attribute or a set of subtype attributes, whose corresponding supertype attributes make up the primary key of an existing physical table, which we say that it is the base table of the group).