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Amazon Ion Schema	/

Amazon Ion Schema defines a grammar and constraints for narrowing the universe of Ion values. A schema consists of zero or more types, and a type is a collection of zero or more constraints over the Ion data model. Aspects of a value not constrained by a type ("open content") are considered valid, which enables loosely-coupled systems to evolve independently.

Once defined, a type can be used to:

• assert that a value meets specific expectations,
• generate developer-friendly APIs for working with data,
• enable efficient analysis over data that conforms to a type,
• and more!

For more information, see the Ion Schema Specification.

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Visit the News page for more announcements related to Ion Schema.

Ion Schema Example {#example}

type::{
  name: Person,
  type: struct,
  fields: {
    title: {
      type: symbol,
      valid_values: [Mr, Mrs, Miss, Ms, Mx, Dr],
    },
    firstName: { type: string, occurs: required },
    middleName: string,
    lastName: { type: string, occurs: required },
    age: { type: int, valid_values: range::[0, 130] },
  },
}

The following values are valid for the type Person:

{
  firstName: "Susan",
  lastName: "Jones",
}
{
  title: Mr,
  firstName: "Jonah",
  middleName: "Q.",
  lastName: "Smith",
  age: 34,
}

The following values are not valid for the type Person:

{
  firstName: "Cathy",        // lastName is required
}
{
  title: Prof,               // Prof is not a valid value for the title field
  firstName: "Jasmine",
  lastName: "Bradford",
}
{
  firstName: "Shami",
  lastName: "Ahmed",
  age: 131,                  // age must be between 0 and 130, inclusive
}