public abstract class BuiltStatement extends RegularStatement
QueryBuilder
.
The actual query string will be generated and cached the first time it is requested,
which is either when the driver tries to execute the query, or when you call certain
public methods (for example RegularStatement.getQueryString(CodecRegistry)
,
getObject(int, CodecRegistry)
).
Whenever possible (and unless you call setForceNoValues(boolean)
, the builder
will try to handle values passed to its methods as standalone values bound to the query
string with placeholders. For instance:
select().all().from("foo").where(eq("k", "the key")); // Is equivalent to: new SimpleStatement("SELECT * FROM foo WHERE k=?", "the key");There are a few exceptions to this rule:
select().all().from("foo").where(eq("k", 1)); // Is equivalent to: new SimpleStatement("SELECT * FROM foo WHERE k=1");One final thing to consider is
custom codecs
. If you've registered
codecs to handle your own Java types against the cluster, then you can pass instances of
those types to query builder methods. But should the builder have to inline those values,
it needs your codecs to convert them to string form
.
That is why some of the public methods of this class take a CodecRegistry
as a
parameter:
BuiltStatement s = select().all().from("foo").where(eq("k", myCustomObject)); // if we do this codecs will definitely be needed: s.forceNoValues(true); s.getQueryString(myCodecRegistry);For convenience, there are no-arg versions of those methods that use
CodecRegistry.DEFAULT_INSTANCE
. But you should only use them if you are sure that
no custom values will need to be inlined while building the statement, or if you have
registered your custom codecs with the default registry instance. Otherwise, you will get
a CodecNotFoundException
.idempotent, NULL_PAYLOAD_VALUE
Modifier and Type | Method and Description |
---|---|
protected static String |
escapeId(String ident)
Deprecated.
preserved for backward compatibility, use
Metadata.quoteIfNecessary(String) instead. |
String |
getKeyspace()
Returns the keyspace this query operates on.
|
Map<String,ByteBuffer> |
getNamedValues(ProtocolVersion protocolVersion,
CodecRegistry codecRegistry)
The named values to use for this statement.
|
Object |
getObject(int i)
Returns the
i th value as the Java type matching its CQL type. |
Object |
getObject(int i,
CodecRegistry codecRegistry)
Returns the
i th value as the Java type matching its CQL type. |
String |
getQueryString(CodecRegistry codecRegistry)
Returns the query string for this statement.
|
ByteBuffer |
getRoutingKey(ProtocolVersion protocolVersion,
CodecRegistry codecRegistry)
Returns the routing key (in binary raw form) to use for token aware
routing of this query.
|
ByteBuffer[] |
getValues(ProtocolVersion protocolVersion,
CodecRegistry codecRegistry)
The positional values to use for this statement.
|
boolean |
hasValues(CodecRegistry codecRegistry)
Whether or not this statement has values, that is if
getValues
will return null or not. |
Boolean |
isIdempotent()
Whether this statement is idempotent, i.e.
|
RegularStatement |
setForceNoValues(boolean forceNoValues)
Allows to force this builder to not generate values (through its
getValues() method). |
String |
toString()
Returns this statement as a CQL query string.
|
boolean |
usesNamedValues()
Whether this statement uses named values.
|
getQueryString, hasValues
disableTracing, enableTracing, getConsistencyLevel, getDefaultTimestamp, getFetchSize, getOutgoingPayload, getReadTimeoutMillis, getRetryPolicy, getSerialConsistencyLevel, isBatchIdempotent, isTracing, setConsistencyLevel, setDefaultTimestamp, setFetchSize, setIdempotent, setOutgoingPayload, setPagingState, setPagingState, setPagingStateUnsafe, setReadTimeoutMillis, setRetryPolicy, setSerialConsistencyLevel
@Deprecated protected static String escapeId(String ident)
Metadata.quoteIfNecessary(String)
instead.public String getQueryString(CodecRegistry codecRegistry)
RegularStatement
Statement
objects.
For example, Statement
objects carry numerous protocol-level
settings, such as the consistency level
to use,
or the idempotence flag
, among others.
None of these settings will be included in the resulting query string.
Similarly, if values have been set on this statement because
it has bind markers, these values will not appear in the resulting query string.
Note: the consistency level was conveyed at CQL level in older versions
of the CQL grammar, but since CASSANDRA-4734
it is now a protocol-level setting and consequently does not appear in the query string.getQueryString
in class RegularStatement
codecRegistry
- the codec registry that will be used if the actual
implementation needs to serialize Java objects in the
process of generating the query. Note that it might be
possible to use the no-arg RegularStatement.getQueryString()
depending on the type of statement this is called on.RegularStatement.getQueryString()
public Object getObject(int i, CodecRegistry codecRegistry)
i
th value as the Java type matching its CQL type.i
- the index to retrieve.codecRegistry
- the codec registry that will be used if the statement must be
rebuilt in order to determine if it has values, and Java objects
must be inlined in the process (see BuiltStatement
for
more explanations on why this is so).i
th value of this statement.IllegalStateException
- if this statement does not have values.IndexOutOfBoundsException
- if i
is not a valid index for this object.getObject(int)
public Object getObject(int i)
i
th value as the Java type matching its CQL type.
This method calls getObject(int, CodecRegistry)
with
CodecRegistry.DEFAULT_INSTANCE
.
It's safe to use if you don't use any custom codecs, or if your custom codecs are in
the default registry; otherwise, use the other method and provide the registry that
contains your codecs.i
- the index to retrieve.i
th value of this statement.IllegalStateException
- if this statement does not have values.IndexOutOfBoundsException
- if i
is not a valid index for this object.public ByteBuffer getRoutingKey(ProtocolVersion protocolVersion, CodecRegistry codecRegistry)
Statement
null
. The routing key is an hint used for token-aware routing (see
TokenAwarePolicy
), and
if provided should correspond to the binary value for the query
partition key. However, not providing a routing key never causes a query
to fail and if the load balancing policy used is not token aware, then
the routing key can be safely ignored.getRoutingKey
in class Statement
protocolVersion
- the protocol version that will be used if the actual
implementation needs to serialize something to compute
the key.codecRegistry
- the codec registry that will be used if the actual
implementation needs to serialize something to compute
this key.null
.public String getKeyspace()
Statement
null
. Firstly, some queries do
not operate inside a keyspace: keyspace creation, USE
queries,
user creation, etc. Secondly, even query that operate within a keyspace
do not have to specify said keyspace directly, in which case the
currently logged in keyspace (the one set through a USE
query
(or through the use of Cluster.connect(String)
)). Lastly, as
for the routing key, this keyspace information is only a hint for
token-aware routing (since replica placement depend on the replication
strategy in use which is a per-keyspace property) and having this method
return null
(or even a bogus keyspace name) will never cause the
query to fail.getKeyspace
in class Statement
null
.public ByteBuffer[] getValues(ProtocolVersion protocolVersion, CodecRegistry codecRegistry)
RegularStatement
RegularStatement.getNamedValues(ProtocolVersion, CodecRegistry)
will return null
.
Values for a RegularStatement (i.e. if either method does not return
null
) are not supported with the native protocol version 1: you
will get an UnsupportedProtocolVersionException
when submitting
one if version 1 of the protocol is in use (i.e. if you've forced version
1 through Cluster.Builder.withProtocolVersion(com.datastax.driver.core.ProtocolVersion)
or you use
Cassandra 1.2).getValues
in class RegularStatement
protocolVersion
- the protocol version that will be used to serialize
the values.codecRegistry
- the codec registry that will be used to serialize the
values.SimpleStatement.SimpleStatement(String, Object...)
public boolean hasValues(CodecRegistry codecRegistry)
RegularStatement
getValues
will return null
or not.hasValues
in class RegularStatement
codecRegistry
- the codec registry that will be used if the actual
implementation needs to serialize Java objects in the
process of determining if the query has values.
Note that it might be possible to use the no-arg
RegularStatement.hasValues()
depending on the type of
statement this is called on.false
if both RegularStatement.getValues(ProtocolVersion, CodecRegistry)
and RegularStatement.getNamedValues(ProtocolVersion, CodecRegistry)
return null
, true
otherwise.RegularStatement.hasValues()
public Map<String,ByteBuffer> getNamedValues(ProtocolVersion protocolVersion, CodecRegistry codecRegistry)
RegularStatement
RegularStatement.getValues(ProtocolVersion, CodecRegistry)
will return null
.
Values for a RegularStatement (i.e. if either method does not return
null
) are not supported with the native protocol version 1: you
will get an UnsupportedProtocolVersionException
when submitting
one if version 1 of the protocol is in use (i.e. if you've forced version
1 through Cluster.Builder.withProtocolVersion(com.datastax.driver.core.ProtocolVersion)
or you use
Cassandra 1.2).getNamedValues
in class RegularStatement
protocolVersion
- the protocol version that will be used to serialize
the values.codecRegistry
- the codec registry that will be used to serialize the
values.SimpleStatement.SimpleStatement(String, Map)
public boolean usesNamedValues()
RegularStatement
usesNamedValues
in class RegularStatement
false
if RegularStatement.getNamedValues(ProtocolVersion, CodecRegistry)
returns null
,
true
otherwise.public Boolean isIdempotent()
Statement
retries
on write timeouts or request errors;speculative executions
.
null
, in which case the driver will default to
QueryOptions.getDefaultIdempotence()
.
By default, this method returns null
for all statements, except for
BuiltStatement
- value will be inferred from the query: if it updates counters,
prepends/appends to a list, or uses a function call or
QueryBuilder.raw(String)
anywhere in an inserted value,
the result will be false
; otherwise it will be true
.
Batch
and BatchStatement
:
Statement.setIdempotent(boolean)
forces a value that overrides calculated value.
Note that when a statement is prepared (Session.prepare(String)
), its idempotence flag will be propagated
to all PreparedStatement
s created from it.isIdempotent
in class Statement
null
to use
QueryOptions.getDefaultIdempotence()
.public String toString()
RegularStatement
Statement
objects.
See the javadocs of RegularStatement.getQueryString()
for more information.toString
in class RegularStatement
RegularStatement.getQueryString()
public RegularStatement setForceNoValues(boolean forceNoValues)
getValues()
method).
By default (and unless the protocol version 1 is in use, see below) and
for performance reasons, the query builder will not serialize all values
provided to strings. This means that getQueryString(CodecRegistry)
may return a query string with bind markers (where and when is at the
discretion of the builder) and getValues(com.datastax.driver.core.ProtocolVersion, com.datastax.driver.core.CodecRegistry)
will return the binary
values for those markers. This method allows to force the builder to not
generate binary values but rather to inline them all in the query
string. In practice, this means that if you call setForceNoValues(true)
, you are guaranteed that getValues()
will
return null
and that the string returned by getQueryString()
will contain no other bind markers than the ones
specified by the user.
If the native protocol version 1 is in use, the driver will default
to not generating values since those are not supported by that version of
the protocol. In practice, the driver will automatically call this method
with true
as argument prior to execution. Hence, calling this
method when the protocol version 1 is in use is basically a no-op.
Note that this method is mainly useful for debugging purpose. In general,
the default behavior should be the correct and most efficient one.forceNoValues
- whether or not this builder may generate values.Copyright © 2012–2017. All rights reserved.