Add docs for setting the CL on prepared statements
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API Documentation
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API Documentation
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=================
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=================
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Cassandra Modules
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-----------------
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.. toctree::
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.. toctree::
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:maxdepth: 2
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:maxdepth: 2
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@@ -123,7 +123,7 @@ when you execute:
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It is translated to the following CQL query:
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It is translated to the following CQL query:
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.. code-block:: SQL
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.. code-block::
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INSERT INTO users (name, credits, user_id)
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INSERT INTO users (name, credits, user_id)
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VALUES ('John O''Reilly', 42, 2644bada-852c-11e3-89fb-e0b9a54a6d93)
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VALUES ('John O''Reilly', 42, 2644bada-852c-11e3-89fb-e0b9a54a6d93)
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@@ -297,7 +297,7 @@ There are a few important things to remember when working with callbacks:
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Setting a Consistency Level
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Setting a Consistency Level
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^^^^^^^^^^^^^^^^^^^^^^^^^^^
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---------------------------
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The consistency level used for a query determines how many of the
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The consistency level used for a query determines how many of the
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replicas of the data you are interacting with need to respond for
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replicas of the data you are interacting with need to respond for
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the query to be considered a success.
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the query to be considered a success.
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@@ -345,3 +345,34 @@ is different than for simple, non-prepared statements (although future versions
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of the driver may use the same placeholders for both). Cassandra 2.0 added
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of the driver may use the same placeholders for both). Cassandra 2.0 added
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support for named placeholders; the 1.0 version of the driver does not support
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support for named placeholders; the 1.0 version of the driver does not support
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them, but the 2.0 version will.
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them, but the 2.0 version will.
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Setting a Consistency Level with Prepared Statements
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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To specify a consistency level for prepared statements, you have two options.
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The first is to set a default consistency level for every execution of the
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prepared statement:
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.. code-block:: python
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from cassandra import ConsistencyLevel
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cluster = Cluster()
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session = cluster.connect("mykeyspace")
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user_lookup_stmt = session.prepare("SELECT * FROM users WHERE user_id=?")
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user_lookup_stmt.consistency_level = ConsistencyLevel.QUORUM
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# these will both use QUORUM
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user1 = session.execute(user_lookup_stmt, [user_id1])[0]
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user2 = session.execute(user_lookup_stmt, [user_id2])[0]
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The second option is to create a :class:`~.BoundStatement` from the
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:class:`~.PreparedStatement` and binding paramaters and set a consistency
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level on that:
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.. code-block:: python
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# override the QUORUM default
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user3_lookup = user_lookup_stmt.bind([user_id3]
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user3_lookup.consistency_level = ConsistencyLevel.ALL
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user3 = session.execute(user3_lookup)
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@@ -1,8 +1,6 @@
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Python Cassandra Driver
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Python Cassandra Driver
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=======================
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=======================
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Contents:
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.. toctree::
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.. toctree::
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:maxdepth: 2
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:maxdepth: 2
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