从erlang插入cassandra [英] inserting from erlang into cassandra

问题描述

我正试图从Erlang R14B02（通过thrift 0.6.1）插入东西到cassandra 0.7.6

I am trying to insert something into cassandra 0.7.6 from Erlang R14B02 (through thrift 0.6.1)

我执行以下操作：

1. 读取记录定义

1. Read record definitions

rr（cassandra_types）。

rr(cassandra_types).

连接到cassandra

Connect to cassandra

{ok，C} = thrift_client_util：new（localhost，9160，cassandra_thrift，[{strict_read ，false}，{strict_write，false}，{framed，true}]）。

{ok, C}=thrift_client_util:new("localhost", 9160, cassandra_thrift,[{strict_read, false}, {strict_write, false}, {framed, true}]).

尝试插入值（timestamp = 1，2 = Quorum）

Try to insert a value (timestamp=1, 2=Quorum)

Reply1 = thrift_client ：call（C，'insert'，[existing_keyspace，new_key，＃columnPath {column_family =existing_column_family，column =existing_column}，new_value，1,2]）。

Reply1 = thrift_client:call(C, 'insert', ["existing_keyspace", "new_key",#columnPath{column_family = "existing_column_family", column = "existing_column"}, "new_value",1,2]).

但是nr3给我一个bad_args错误（1和2完美工作）。

But nr3 gives me a bad_args error (1 and 2 work perfectly). What would be the right arguments?

推荐答案

有关不支持的语言的API信息主要在它们的 Cassandra Thrift API文档。

What API information there is for unsupported languages is largely in their Cassandra Thrift API documentation.

在Cassandra 0.7中， t提供大多数操作的键空间，因此 insert 只需要 [Key，ColumnPath，Column，ConsistencyLevel] 。在尝试插入之前，您需要调用 set_keyspace 。在erlang插入是

In Cassandra 0.7, you don't supply the keyspace for most operations, so insert just takes [Key, ColumnPath, Column, ConsistencyLevel]. You need to call set_keyspace before attempting the insert. The insert in erlang would be

Reply1 = thrift_client:call(C, 'insert',
                            [SomeKey,
                             #columnPath{column_family = "existing_column_family",
                                         column = "existing_column"},
                             #column{name="existing_column",
                                     value="new_value",timestamp=1},
                             ?cassandra_ConsistencyLevel_QUORUM]).

您的示例缺少插入我想的行键。

Your example is missing the row key for the insert I think too.

另外，请确保你总是更新C的值 - 它在每次thrift_client调用后改变。

As an aside, make sure you always update the value of C - it changes after every thrift_client call.

？cassandra_ConsistencyLevel_QUORUM是从内存。

?cassandra_ConsistencyLevel_QUORUM is 2 from memory.

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