Database Reference
In-Depth Information
Multivalued data types
DynamoDB supports complex data types that are formed by using one or more scalar data
types. There are three multivalued data types supported by DynamoDB:
• String sets
• Number sets
• Binary sets
In the previous section, we had seen one example of the
Book
table having the
authors
attribute. This
authors
attribute is a good example of a string set. Similarly, number sets
and binary sets can also be defined and used. An example of a number set would be the
marks
attribute in a
Student
table, and an example of a binary set would be
images
included in the
Chapter
table.
As these data types are sets, the values in a set must be unique. DynamoDB does not put
any order on the attribute values of a set. It also does not support empty sets.
Now, that we have seen primary keys, secondary indexes, and data types in DynamoDB,
let's start discussing operations on tables, items, and attributes.