使用datastax Java驱动程序为where in子句绑定数据 [英] use datastax java driver to bind data for where in clause

问题描述

我知道有人问过这个问题（ http://www.datastax.com/support-forums/topic/java-driver-cql-3-bound-statements-in-clause#post-13114 ，< a href = https://stackoverflow.com/questions/16918853/prepared-statement-with-collection-in-in-clause-in-datastax-cassandra-cql-driver>在Datastax的IN子句中带有集合的预声明Cassandra CQL驱动程序）

I know somebody has ask this question (http://www.datastax.com/support-forums/topic/java-driver-cql-3-bound-statements-in-clause#post-13114, Prepared Statement with collection in IN clause in Datastax Cassandra CQL driver)

但是，我仍然不知道如何绑定数据。以
为例，我的prepareStatement是

However, I still do not know how to bind data. for example, my preparedStatement is

select * from cf where key in (?)

我想要的是绑定数据，而cql看起来像是

What I want is bind data and the cql is looks like

select * from cf where key in ('key1', 'key2')

现在我有一个boundStatement。

Now I have a boundStatement.

当我使用boundStatment.bind（）api时。我尝试绑定？

when I use boundStatment.bind() api. I try to bind ? with a List or a Array, however , it says:

列值是varchar类型，不能设置为列表

Column value is of type varchar, cannot set to a list

好，我设置一个字符串并使用boundStatement.bind像这样：

Ok, I set a string and use boundStatement.bind like this:

boundStatement.bind("'key1','key2'");

没有例外，但是resultSet为空。为什么？我认为是因为驱动程序将其解析为

There is no exception, but the resultSet is empty. Why? I think because the driver parse it as

select * from cf where key in (''key1', 'key2'')

（请注意，因为它认为所有的 key1和 key2都是

(notice a redundant quote because it thinks all the "'key1',and 'key2'" is a string).

所以，我知道datastax在子句中有支持。但是我找不到一些例子..

So, I know datastax has support in clause. but I can not find some examples ..

有什么可以帮到我吗？
谢谢！

Can any help me? Thanks!

推荐答案

正确的语法是：

SELECT * FROM cf WHERE key IN ?

这将允许您为查询参数绑定列表。

That will allow you to bind a List for the query parameter.

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