Support multiple Update operations for the same column

[ivan-zaitsev]

Update stores one column name as key and one operation as value.

spring-data-cassandra/spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/query/Update.java

Line 49 in 67d8e59

private final Map<ColumnName, AssignmentOp> updateOperations;

Because of this it is not possible to update several keys for column with map type.

Example of code:

CREATE TABLE data (fields map<VARCHAR, VARCHAR>);

List<Update.AssignmentOp> updateOperations = new LinkedList<>();
updateOperations.add(new Update.SetAtKeyOp(ColumnName.from("map"), "key1", "value1"));
updateOperations.add(new Update.SetAtKeyOp(ColumnName.from("map"), "key2", "value2"));
Update update = Update.of(updateOperations);

OR

Update update = Update.empty()
        .set("map").atKey("key1").to("value1")
        .set("map").atKey("key2").to("value2");

only one of operations will be present in update object.

[ivan-zaitsev]

As a workaround possible to create custom ColumnName which will return different equals/hashCode to identical column names.

[mp911de]

This is indeed a limitation of the current implementation. Our API should be able to support multiple operations per column and that will be a neat enhancement.

[nemogpt]

Hi @mp911de Could you confirm if this still needs to be fixed?

[mp911de]

Confirmed. Update should contain a List of operations and and we need to define what happens if you try to update the same element (same column or same key in a map) twice. Replacing (as of today) seems a good idea, we also should document what we're doing.

[nemogpt]

could you pls assign this ticket to me, so that i can start with it?