Access the elements of a collection

Table 1. DataBlade API functions that access collection data types
DataBlade API collection function	Description
mi_collection_copy()	Creates a copy of an existing open collection
mi_collection_delete()	Deletes an element from a collection
mi_collection_fetch()	Fetches an element from a collection
mi_collection_insert()	Inserts a new element into an open collection
mi_collection_update()	Updates an element in an open collection

Position the cursor
When you open a collection cursor with mi_collection_open(), the cursor position points to the first element of the collection.

Insert an element
You insert an element into an open collection with the mi_collection_insert() function. You can perform an insert operation only on a read/write cursor. An insert is not valid on a read-only cursor.

Fetch an element
You fetch an element from an open collection with the mi_collection_fetch() function. You can perform a fetch operation on a read/write or a read-only cursor.

Update a collection
You update an element in an open collection with the mi_collection_update() function. You can perform an update operation only on a read/write cursor. An update is not valid on a read-only cursor.

Delete an element
You delete an element from an open collection with the mi_collection_delete() function. You can perform a delete operation only on a read/write cursor. A delete is not valid on a read-only cursor.

Determine the cardinality of a collection
The DataBlade API provides the mi_collection_card() function for obtaining the number of elements in a collection (its cardinality).