cassandra - 如何在 Cassandra(特别是 CQLSH)中将字符串或文本作为 blob 插入？

Question

我试图在 CQLSH 中插入文本或一些字符串作为 blob 以进行测试

insert into test_by_score (commit, delta, test, score)
       values (textAsBlob('bdb14fbe076f6b94444c660e36a400151f26fc6f'), 0,
       textAsBlob('{"prefix": "enwiki", "title": "\"Aghnadarragh\""}'), 100);

它并没有真正起作用，因为在我做了之后:

select * from test_by_score where commit = 0x0b5db8b91bfdeb0a304b372dd8dda123b3fd1ab6;

它说有 0 列......这有点出乎意料(因为它没有向我抛出错误)但我猜 textAsBlob 在 cqlsh 中不是一个东西。那么有人知道如何做到这一点吗？

架构:

CREATE TABLE IF NOT EXISTS test_by_score (
    commit blob, 
    delta int, 
    score int, 
    test blob, 
    PRIMARY KEY(commit, delta, test)
);

我有点不情愿地发布了我的架构，因为我相信我的问题并不是关于这个特定的架构。我只想知道的是，如果有一列包含 blob，是否可以通过先将字符串更改为 blob 然后将其插入 cqlsh 来在该位置插入字符串？

Answer 1

以下似乎有效。您的 WHERE您的情况SELECT语句可能试图访问不正确的十六进制 0x0b5db8b91bfdeb0a304b372dd8dda123b3fd1ab6 .

DROP KEYSPACE example;
CREATE KEYSPACE example WITH replication = {'class':'SimpleStrategy', 'replication_factor':1};
USE example;

CREATE TABLE IF NOT EXISTS test_by_score (
    commit blob, -- blob representing the commit hash
    delta int, -- how much the scores have changed
    score int, -- the test score, which is determined by the client
    test blob, -- blob for the test
    PRIMARY KEY(commit, delta, test)
);

INSERT INTO test_by_score  (commit, delta, test, score) VALUES 
  (textAsBlob('bdb14fbe076f6b94444c660e36a400151f26fc6f'), 0, textAsBlob('{"prefix": "enwiki", "title": "\"Aghnadarragh\""}'), 100
);

INSERT INTO test_by_score (commit, delta, test, score) VALUES (
  textAsBlob('cdb14fbe076f6b94444c660e36a400151f26fc6f'), 0, textAsBlob('{"prefix": "enwiki", "title": "\"Aghnadarragh\""}'), 100
);

INSERT INTO test_by_score (commit, delta, test, score) VALUES (
  textAsBlob('adb14fbe076f6b94444c660e36a400151f26fc6f'), 0, textAsBlob('{"prefix": "enwiki", "title": "\"Aghnadarragh\""}'), 100
);

抓取所有行

SELECT * FROM example.test_by_score 

选择特定行。

SELECT * FROM example.test_by_score 
  WHERE commit = 0x62646231346662653037366636623934343434633636306533366134303031353166323666633666;