#Get values of icollections code#

If an instance of the parent class holds an empty collection (one that contains no elements), the ID for that instance does not appear in the child table, such as the instance above where ID equals 11. Sample Projection of an Array Property Person (ID) One contains array members for all the instances of the class its name is that of array property ( Siblings, in the example).Д¬ontinuing the example of the Person class with an array property called Siblings, the projection of Person includes a Person_Siblings child table with the following entries: One contains the identifier for each array member its name is always element_key. One contains the ID of the corresponding instance of the parent class the name of this column is that of the class containing the array ( Person, in the example). The child table contains the following three columns: Tablename is the SqlTableName of the parent class (if specified) or the short name of the parent class (if SqlTableName is not specified).ДЇieldname is the SqlFieldName of the array property (if specified) or the name of the array property (if SqlFieldName is not specified).ДЇor example, a Person class with an array property called Siblings has a projection as a child table called вЂњPerson_SiblingsвЂќ.

#Get values of icollections code#

Tablename_fieldname Copy code to clipboard This copies the contents of the source into the recipient (not the OREF of the collection itself). To copy the items in one collection into another collection, set the recipient collection equal to the source collection. Copy link to this section Copying Collection Data Note that the details are not the same as for the list classes. For details, see the class reference for these classes. These classes provide instance methods such as GetAt(), Find(), GetPrevious(), GetNext(), and Remove().

%Collection.ArrayOfObj (if the array element is an object class) %Collection.ArrayOfDT (if the array element is a data type class) When you create an array property as described earlier, the property itself is an object that provides the instance methods of one of the following classes, depending on the property definition: Copy link to this section Working with Array Properties SetAt ( 'yellow', 2 ) Copy code to clipboardДЇor other methods, such as Find(), RemoveAt(), and others, see the class reference for %Collection.ListOfDT and %Collection.ListOfObj. To define a list property, add a property as follows:Дo person. Copy link to this section Defining Collection Properties Note that collection classes are object classes. This chapter focuses on %Collection classes, but the details are similar for the %Library classes. InterSystems IRIS provides a different set of collection classes for use when you need a stand-alone collection, for example, to pass as an argument to a method these are classes in the %Library package.Д®ach set of classes provides methods and properties that you can use to add collection items, remove collection items, count collection items, and so on.

InterSystems IRIS uses a set of collection classes as an interface to collection properties these are classes in the %Collection package. For arrays, keys can have arbitrary values, and you specify them for each element.

For list collections, the system generates sequential integer keys. There are two kinds of collections: lists and arrays.Д®ach item in a collection is called an element and its position within the collection is called a key. This chapter describes collections, especially collection properties.ДЄlso see the chapters вЂњ Defining and Using Literal Properties,вЂќ вЂњ Working with Streams,вЂќ вЂњ Defining and Using Object-Valued Properties,вЂќ вЂњ Defining and Using RelationshipsвЂќ, and вЂњ Using and Overriding Property Methods.вЂќ Copy link to this section Introduction to CollectionsДЄ collection contains a set of individual elements, all of the same type. You can also define stand-alone collections for other purposes, such as for use as an method argument or return value. You can define collection properties in any object class. The elements can be literal values or can be objects. InterSystems IRISВ® supports collections, which provide a way to work with a set of elements, all of the same type.

Creating and Using Stand-Alone Collections.

Controlling the SQL Projection of Collection Properties.