Cassandra 选择性复制 [英] Cassandra selective copy

问题描述

我想将列族中的选定行复制到 .csv 文件.copy 命令仅可用于将列或整个表转储到文件中，而无需 where 子句.有没有办法在复制命令中使用 where 子句?

I want to copy selected rows from a columnfamily to a .csv file. The copy command is available just to dump a column or entire table to a file without where clause. Is there a way to use where clause in copy command?

我想到的另一种方式是，

Another way I thought of was,

做插入到table2()值(select * from table1 where )；"然后将 table2 转储到 .csv ，这也是不可能的.

Do "Insert into table2 () values ( select * from table1 where <where_clause>);" and then dump the table2 to .csv , which is also not possible.

任何帮助将不胜感激.

推荐答案

copy 中没有办法制作 where 子句，但是可以用这个方法:

There are no way to make a where clause in copy, but you can use this method :

echo "select c1,c2.... FROM keySpace.Table where ;"|bin/cqlsh > output.csv

echo "select c1,c2.... FROM keySpace.Table where ;" | bin/cqlsh > output.csv

它允许您将结果保存在 output.csv 文件中.

It allows you to save your result in the output.csv file.

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