DtoColumns Collection

A collection of DtoColumn objects representing all the columns in a table.

Properties


Count	Returns the number of members in a collection.
Item	Returns a specific member of a DtoColumns collection.

Methods

Add method 
Remove method 
Clear method

Remarks

You obtain this collection from a property of the DtoTable Object object.

Use the Count property to find the number of members in the collection.

Example

Dim dictionary as new DtoDictionary 
dictionary.Open("c:\pvsw\demodata") 
students_table = dictionary.GetTable("STUDENT") 
students_cols = students_table.Columns

Add method

Add an item to a DtoColumns collection.

Syntax

status = Collection.Add(Object)

Arguments


Collection	DtoColumns collection to which to add object.
Object	A new DtoColumn object.

Return Values


result	DtoResult long value indicating the result of the method call. Use the Error property of the DtoSession Object to obtain a description for the result.

Remarks

This method takes a parameter of type DtoColumn. Therefore, you are responsible for first instantiating the object and setting its properties before adding it to the collection.

Note
You cannot use this method to add columns to preexisting Pervasive.SQL tables. This method does not alter data or DDF files, and can only be used to add columns in memory before a table is created. See the example for AddTable method as a reference.

Remove method

Removes an item from a DtoColumns collection.

Syntax

Collection.Remove(column)

Arguments


Collection	DtoColumns collection from which to remove object.
column	A variant containing either the index (starting with 1) or the name of the item you wish to remove from the DtoColumns collection

Return Values


result	DtoResult long value indicating the result of the method call. Use the Error property of the DtoSession Object to obtain a description for the result.

Remarks

You can pass either a column name or the 1-based ordinal of the item in the DtoColumns collection.

Note
You cannot use this method to remove columns from preexisting Pervasive.SQL tables. This method does not alter data or DDF files, and can only be used to remove columns in memory before a table is created. See the example for AddTable method as a reference.

Clear method

Removes all items from a DtoColumns collection.

Syntax

result = Collection.Clear

Arguments


In	Collection	DtoColumns or DtoIndexes collection obtained from a DtoTable object

Return Values


result	DtoResult long value indicating the result of the method call. Use the Error property of the DtoSession Object to obtain a description for the result.

Remarks

This method removes all the columns from a table in memory.

Note
You cannot use this method to remove columns from preexisting Pervasive.SQL tables. This method does not alter data or DDF files, and can only be used to remove all columns in memory before a table is created. See the example for AddTable method as a reference.