使用Python Cassandra模塊進行參數化查詢

Question

我一直在嘗試Python支持參數化查詢的CQL插件（http://code.google.com/a/apache-extras.org/p/cassandra-dbapi2/）。從他們的文檔：

import cql 
connection = cql.connect(host, port, keyspace) 
cursor = connection.cursor() 
cursor.execute("CQL QUERY", dict(kw='Foo', kw2='Bar', etc...)) 

我的問題是它可以參數化，並在循環中多次執行相同的查詢，什麼方法看起來想實現這一目標。很抱歉，但文檔很少，所以我搜索有關的答案...

Answer 1

看看在tests代碼爲更多的例子

import cql 
connection = cql.connect(host, port, keyspace) 
cursor = connection.cursor() 

query = "UPDATE StandardString1 SET :c1 = :v1, :c2 = :v2 WHERE KEY = :key" 
cursor.execute(query, dict(c1="ca1", v1="va1", c2="col", v2="val", key="ka")) 
cursor.execute(query, dict(c1="cb1", v1="vb1", c2="col", v2="val", key="kb")) 
cursor.execute(query, dict(c1="cc1", v1="vc1", c2="col", v2="val", key="kc")) 
cursor.execute(query, dict(c1="cd1", v1="vd1", c2="col", v2="val", key="kd")) 

或者更具體地說，你的問題有關在運行它循環：

import cql 
connection = cql.connect(host, port, keyspace) 
cursor = connection.cursor() 

query = "UPDATE StandardString1 SET :c1 = :v1, :c2 = :v2 WHERE KEY = :key" 
values = [dict(c1="ca1", v1="va1", c2="col", v2="val", key="ka"), 
      dict(c1="cb1", v1="vb1", c2="col", v2="val", key="kb"), 
      dict(c1="cc1", v1="vc1", c2="col", v2="val", key="kc"), 
      dict(c1="cd1", v1="vd1", c2="col", v2="val", key="kd")] 

for value in values: 
    cursor.execute(query, value)