Data Shaping Technology-Shape Append command

Source: Internet
Author: User
Tags table name
The Shape APPEND command assigns the child Recordset to the Value attribute of the Field object in the parent Recordset.
Syntax
SHAPE {parent-command} [[AS] parent-alias]
APPEND ({child-command} [AS] child-alias
RELATE parent-column TO child-column...) [[AS] chapter-alias]...
Composition Description
The command consists of the following components:
Parent-command, child-command is one of the following.
The query command in the angle brackets ("{}") returns the Recordset object. The syntax of a command published to the basic data provider depends on the requirements of the provider. Although ADO does not require any specified query language, it usually uses a Structured Query Language (SQL ). Parentheses ("()") are required keywords that append the subset column to the parent that references the Recordset returned by the query command.
The name of the previously formed Recordset.
Another Shape command.
The TABLE keyword, followed by the TABLE name.
The parent-column is the column in The Recordset returned by the parent-command.
Child-column: the column in Recordset returned by child-command.
... The "parent-column TO child-column" clause is actually a list and is separated by commas.
Chapter-alias for reference to columns appended to the parent.
Parent-alias, which references the parent Recordset.
The child-alias that references the child Recordset.
... The clause after the APPEND keyword is actually a list (each clause is separated by commas), and the definition is appended to another parent column.
Operation
Issue the parent-command and return the parent Recordset. Then the child-command is sent and the child Recordset is returned.
For example, parent-command can return the company's customer Recordset from the customer table, while child-command returns the order Recordset of all customers from the order table.
Generally, the parent and child Recordset objects must each have columns used to associate the parent and child. Columns are named in the RELATE clause. parent-column takes precedence and child-column takes precedence. In each Recordset, columns can have different names, but the same information must be referenced to specify meaningful relationships. For example, Customers and Orders Recordsets can have the customerID field at the same time.
Data ing adds a subset column to the parent Recordset. The value in the subset column is a reference to the column in the child Recordset. The child Recordset satisfies the RELATE clause. That is, the parent-column in the given parent row has the same value as the child-column in all the rows of the subset.
When you access the reference in the subset column, ADO will automatically retrieve the Recordset represented by the reference. Note that although all subrecordsets have been retrieved, the subset (chapter) only indicates the subset of rows.
If the appended column does not have chapter-alias, its name is automatically generated. The Field object of the column will be appended to the Fields set of The Recordset object, and its data type will be adChapter.

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