ADO: ActiveX Data Objects

Shaping Commands

Shaping commands allow you to create hierarchical recordsets in two ways. The first way is done through the APPEND command. The APPEND command can be used to attach a child recordset to a parent based upon a common field value or values. One field value in the parent recordset is equivalent to all of the field values in its child recordset. The APPEND command can add not only chapter columns (pointing to child recordsets), it can also add calculated, aggregated, and fabricated columns.

The second method of creating hierarchical recordsets in ADO is to use the COMPUTE command. This method generates a parent recordset from a child recordset. Parent columns are created by aggregation operations over a column of the child, an expression on an entire row of the recordset, a grouping column (using the keyword BY), or by creating a new blank column. In addition, one of the parent recordset’s columns must be a chapter column pointing to the child recordset. The parent can also be a calculated, aggregated, or fabricated column.

APPEND Command

The APPEND command is used to append a child recordset to a column within a parent recordset. The syntax of the APPEND command is as follows:

SHAPE {parent-command} [[AS] parent-alias]
APPEND ({child-command} [AS] child-alias
RELATE parent-column TO child-column) [[AS] chapter-alias]...

In this syntax, the parent-command and child-commands can be one of four things:

• A command that is translated by the underlying data provider (usually ...