cassandra 查询keyspace和表

Posted by abloz on June 10, 2015

周海汉 2015.6.10

查询keyspace,可以在系统表中查询:

cqlsh> use system;

cqlsh:system> select * from schema_keyspaces;

cqlsh:system> select * from schema_keyspaces;

 keyspace_name         | durable_writes | strategy_class                              | strategy_options
-----------------------+----------------+---------------------------------------------+----------------------------
 Usergrid_Applications |           True | org.apache.cassandra.locator.SimpleStrategy | {"replication_factor":"1"}
              Usergrid |           True | org.apache.cassandra.locator.SimpleStrategy | {"replication_factor":"1"}
                system |           True |  org.apache.cassandra.locator.LocalStrategy |                         {}
            mykeyspace |           True | org.apache.cassandra.locator.SimpleStrategy | {"replication_factor":"1"}
         system_traces |           True | org.apache.cassandra.locator.SimpleStrategy | {"replication_factor":"2"}

(5 rows)

查询keyspace,也可以用describe

cqlsh:Usergrid> DESCRIBE KEYSPACES;

“Usergrid_Applications” mykeyspace system “Usergrid” system_traces

使用keyspace时可能需要引号。

cqlsh:mykeyspace> use Usergrid;

InvalidRequest: code=2200 [Invalid query] message=”Keyspace ‘usergrid’ does not exist”

此处必须加双引号,才能正确切换keyspace

cqlsh:mykeyspace> use “Usergrid”;

cqlsh:Usergrid>

显示表名。

cqlsh:Usergrid> DESCRIBE TABLES;

“Tokens” “Applications” “PrincipalTokens” “Properties”

cqlsh:Usergrid> DESCRIBE  SCHEMA

CREATE KEYSPACE “Usergrid_Applications” WITH replication = {‘class’: ‘SimpleStrategy’, ‘replication_factor’: ‘1’}  AND durable_writes = true;

CREATE TABLE “Usergrid_Applications”.”Entity_Properties” (

。。。