我将在文件库中表达这一想法:
SELECT key,value
FROM table1
WHERE value > 10
或者我们是否总是需要知道关键?
I suppose you can use secondary indexes which are available since version 0.7 of casssandra. You might also checkout the following answer: Cassandra and Secondary-Indexes, how do they work internally?
建议只为低正心一栏使用二级指数,这意味着没有许多不同数值的栏目(例如,地位或优先权等通常只有诸如高、中、低等不同数值的栏目)。
In case you are using Hector as your cassandra client you can find information here how to use them: https://github.com/rantav/hector/wiki/User-Guide
Yes, of course, for example, you can use *
select * from CF where value = 10
If you use the Hector API (e.g. CqlQuery), you can get a list of rows back from this query.
Note, currently for secondary indexes, you must have at least one equality conditional, so your query with just value > 10 would not work. See this question
$db_user="root"; $db_host="localhost"; $db_password="root"; $db_name = "fayer"; $conn = mysqli_connect($db_host,$db_user,$db_password,$db_name) or die ("couldn t connect to server"); // perform query ...
I am in the early stages of developing a database-driven system and the largest part of the system revolves around an inheritance type of relationship. There is a parent entity with about 10 columns ...
I m writing a Java web app in my free time to learn more about development. I m using the Stripes framework and eventually intend to use hibernate and MySQL For the moment, whilst creating the pages ...
Does anybody know if it is possible to move some (not all) users from one ASP.NET membership database to another? (for the purposes of migrating some users to another database on another machine, but ...
Is it because of size? By the way, what is the limit of the size?
I am trying to join two tables that reside in two different databases. Every time, I try to join I get the following error: An association from the table xxx refers to an unmapped class. If the ...
For example, I have a table, and there is a column named Tags . I want to know if value programming exists in this column. How can I do this in ADO.NET? I did this: OleDbCommand cmd = new ...
I m trying to migrate one of my PHP projects to Doctrine. I ve never used it before so there are a few things I don t understand. In my current code, I have a class similar to this: class ...