Materialised view error in Cassandra

问题

I am new to Cassandra, I am trying to create a table and materialized view. but it not working.

My queries are:

-- all_orders

create table all_orders (
    id uuid,
    order_number bigint,
    country text,
    store_number bigint,
    supplier_number bigint,
    flow_type int,
    planned_delivery_date timestamp,
    locked boolean,
    primary key ( order_number,store_number,supplier_number,planned_delivery_date ));

-- orders_by_date

CREATE MATERIALIZED VIEW orders_by_date AS 
    SELECT 
        id,
        order_number,
        country,
        store_number,
        supplier_number,
        flow_type,
        planned_delivery_date,
        locked,
    FROM all_orders
    WHERE planned_delivery_date IS NOT NULL AND order_number IS NOT NULL 
    PRIMARY KEY ( planned_delivery_date )
    WITH CLUSTERING ORDER BY (store_number,supplier_number);

I am getting an exception like this:

SyntaxException: <ErrorMessage code=2000 [Syntax error in CQL query]
message="line 1:7 no viable alternative at input 'MATERIALIZED' ([CREATE] MATERI
ALIZED...)">

回答1:

Materialized Views in Cassandra solves the use case of not having to maintain additional table(s) for querying by different partition keys. But comes with following restrictions

Use all base table primary keys in the materialized view as primary keys.
Optionally, add one non-PRIMARY KEY column from the base table to the materialized view's PRIMARY KEY.
Static columns are not supported as a PRIMARY KEY.

More documentation reference here.

So the correct syntax in your case of adding the materialized view would be

CREATE MATERIALIZED VIEW orders_by_date AS 
    SELECT  id, 
            order_number, 
            country, 
            store_number, 
            supplier_number, 
            flow_type, 
            planned_delivery_date, 
            locked
            FROM all_orders
            WHERE planned_delivery_date IS NOT NULL AND order_number IS NOT NULL AND store_number IS NOT NULL AND supplier_number IS NOT NULL
            PRIMARY KEY ( planned_delivery_date, store_number, supplier_number, order_number );

Here planned_delivery_date is the partition key and the rows are ordered by store_number, supplier_number, order_number (essentially the clustering columns). So there isn't a mandatory requirement to add "CLUSTERING ORDER BY" clause here.

来源：https://stackoverflow.com/questions/48441454/materialised-view-error-in-cassandra

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cassandra

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cql3