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Totktonada opened this issue Aug 2, 2019 · 3 comments
Open

Provide a result set object for noSQL API #211

Totktonada opened this issue Aug 2, 2019 · 3 comments
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enhancement

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@Totktonada
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There are several reasons to do so:

  • It allow a user to get a value in an exact type (s)he requested. See also this discussion.
  • It allows to avoid explicit type convertions on a user's end (now we return results just as List<?> and types inside are mapped from msgpack values).
  • This is precondition to support server side cursors in the future (however tarantool does not support them for now).

I think we need to support type convertions under hood at least for integers: say, 16 bits value can be acquired as 32 bits one. We should detect an overflow and raise an exception in the case.

It worth to keep in a mind ResultSet API from JDBC. I hope there are more things that are handled in related JDBC API to aware of, except type conversions.

We may catch an API from the alternative connector: https://github.com/isopov/tarantool-java-driver/blob/88485aca0895f4069517284c6e3e79caf00b0024/tarantool-driver/src/test/java/com/sopovs/moradanen/tarantool/TarantoolClientImplTest.java#L413-L418
@Totktonada
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After #7 we can also provide a way to extract a field from a tuple by its name, not only by an id.

@nicktorwald nicktorwald modified the milestone: JDBC MVP Sep 26, 2019
nicktorwald added a commit that referenced this issue Oct 11, 2019
@nicktorwald
ResultSet API for TarantoolClient
8fd6068 
Extend an TarantoolClient API to be able to get data using type safe
methods and conversions.

Closes: #211
@nicktorwald nicktorwald mentioned this issue Oct 11, 2019
Closed
nicktorwald added a commit that referenced this issue Dec 17, 2019
@nicktorwald
types: ResultSet API for TarantoolClient
416a303 
This commit introduces a new API to handle TarantoolClient result. The
concept is similar to the JDBC ResultSet in terms of a getting the data
using rows ans columns. Instead of a guessing-style processing the
result via List<?>, TarantoolResultSet offers set of typed methods to
retrieve the data or get an error if the result cannot be represented as
the designated type.

Latter case requires to declare formal rules of a casting between the
types. In scope of this commit it is supported 11 standard types and
conversions between each other. These types are byte, short, int, long,
float, double, boolean, BigInteger, BigDecimal, String, and byte[].

Closes: #211
nicktorwald added a commit that referenced this issue Dec 17, 2019
@nicktorwald
types: ResultSet API for TarantoolClient
ce50492 
This commit introduces a new API to handle TarantoolClient result. The
concept is similar to the JDBC ResultSet in terms of a getting the data
using rows ans columns. Instead of a guessing-style processing the
result via List<?>, TarantoolResultSet offers set of typed methods to
retrieve the data or get an error if the result cannot be represented as
the designated type.

Latter case requires to declare formal rules of a casting between the
types. In scope of this commit it is supported 11 standard types and
conversions between each other. These types are byte, short, int, long,
float, double, boolean, BigInteger, BigDecimal, String, and byte[].

Closes: #211
@Totktonada
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Another case, which appears from time to time: a user of the Java connector wants to get binary response data as byte[], but the connector parses msgpack string values into String and may report a unicode decoding error.

@Totktonada
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NB: We should give a user API to unpack call / eval result in the similar way as for a value from a result set.

@Totktonada Totktonada mentioned this issue May 15, 2020
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ResultSet API for TarantoolClient tarantool/tarantool-java
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@Totktonada @nicktorwald