Improve mapping specifications between Cassandra & Java [DATACASS-128]

[spring-projects-issues]

Matthew T. Adams opened DATACASS-128 and commented

CassandraSimpleTypeHolder's static block initializes Cassandra/Java type mappings by iterating over the value returned by Cassandra's DataType.allPrimitiveTypes(). The order in which DataType instances are returned is not guaranteed, and, further, multiple Cassandra types map to a single Java type.

Cassandra types ASCII, VARCHAR & TEXT map to java.lang.String; BIGINT & COUNTER map to java.lang.Long; BLOB & CUSTOM map to java.nio.ByteBuffer; UUID & TIMEUUID map to java.util.UUID.

This means that if, during schema generation, the generator encounters a Java type that maps to multiple C* types (String, Long, ByteBuffer, or UUID), the generator can't know the C* type that should be used; it must be told.

We'll consider adding an attribute ??? dataType() default ??? with an appropriate default to the @Column annotation so that developers can disambiguate the C* type to be used. We can't use DataType.Name for the attribute's type since there's no enum value meaning "no type".

If schema generation is not being used, then this issue is moot, provided that the Java type of the property is mapped appropriately to the target column's type by the DataStax driver

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Affects: 1.0 M1 (Dijkstra), 1.0 RC1 (Dijkstra)

Issue Links:

• DATACASS-271 Upgrade to Cassandra 3.0.0

• DATACASS-285 Add support for counter columns

• DATACASS-280 Refactor Cassandra query execution and mapping to consolidate mapping

• DATACASS-83 Support custom field mappings

• DATACASS-375 UUID should map to Cassandra's uuid type and not timeuuid

Referenced from: commits 183c502

[spring-projects-issues]

Matthew T. Adams commented

This issue arose from reviews of #7 & #8, which are now closed and refer to this issue

[spring-projects-issues]

Mark Paluch commented

String and Long/long types were tied to a specific type. String property map to text column type and long properties map to bigint. These changes were part of DATACASS-280 and DATACASS-271.

Users can specify the column type with @CassandraType(type = …) to override defaults.

We should inspect ByteBuffer and UUID (currently maps to timeuuid by default) types whether they should map to different Cassandra types by default

[spring-projects-issues]

Mark Paluch commented

Type mapping fixed via DATACASS-271, DATACASS-280, DATACASS-375