Type alias SomePKey

Overview

Represents some primary key in a table. This is a generic type that represents some (any) table primary key with any number & types of columns. All it asks for is that the primary key be an object with string keys and any values.

Keep in mind the logical constraints, however:

• This should be a subset of the table's schema
• Primary key values must be only scalar types

✏️Note: There is no distinction between partition and clustering keys in this type.

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Constructing this type

Often, you may want to construct this type using the Pick utility type, to select only the fields of the schema which are in the primary key.

Example

interface MyTableSchema {
  partitionKey: string;
  clusteringKey: number;
  otherField: Map<string, string>;
}

type MyTablePrimaryKey = Pick<MyTableSchema, 'partitionKey' | 'clusteringKey'>;

const table = db.table<MyTableSchema, MyTablePrimaryKey>('my_table');
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However, if you are constructing a table with Db.createTable, you may use the InferTablePrimaryKey utility type to infer the TS-equivalent type of the primary key from the CreateTableDefinition.

Example

const MyTableSchema = Table.schema({
  columns: {
    partitionKey: 'text',
    clusteringKey: 'int',
    otherField: 'map<text, text>',
  },
  primaryKey: {
    partitionBy: ['partitionKey'],
    partitionSort: { clusteringKey: 1 },
  },
});

type MyTableSchema = typeof MyTableSchema;
type MyTablePrimaryKey = InferTablePrimaryKey<typeof MyTableSchema>;

const table = db.createTable<MyTableSchema, MyTablePrimaryKey>('my_table', {
  definition: MyTableSchema,
});
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Using this type

This type is used as the second type parameter of the Table class.

If this is not provided, then the table's primary key type will default to Partial<Schema> where Schema is the schema of the table.

See

• InferTablePrimaryKey
• Db.createTable
• SomeRow
• Table