com.orientechnologies.jdo
Class oQuery

java.lang.Object
  com.orientechnologies.jdo.oQuery

All Implemented Interfaces:

Query, java.io.Serializable

public class oQuery

extends java.lang.Object

implements Query

Query implementation. It supports all languages supported by Orient (JDOQL and ORQL).

See Also:

Serialized Form

Constructor Summary

oQuery(oPersistenceManager iManager)
Create an empty query passing the PersistenceManager associated.

Method Summary

void	close(java.lang.Object p0) Close a query result and release any resources associated with it.
void	closeAll() Close all query results associated with this Query instance, and release all resources associated with them.
void	compile() Compile the query.
void	declareImports(java.lang.String parm1) Set the import statements to be used to identify the fully qualified name of variables or parameters.
void	declareParameters(java.lang.String parm1) Declare the list of parameters query execution.
void	declareVariables(java.lang.String parm1) Declare the unbound variables to be used in the query.
java.lang.Object	execute() Execute the query returning a collection with results or the persistent object if the query returns only one object.
java.lang.Object	execute(java.lang.Object parm1) Execute the query and return the filtered Collection.
java.lang.Object	execute(java.lang.Object parm1, java.lang.Object parm2) Execute the query and return the filtered Collection.
java.lang.Object	execute(java.lang.Object parm1, java.lang.Object parm2, java.lang.Object parm3) Execute the query and return the filtered Collection.
java.lang.Object	executeWithArray(java.lang.Object[] parm1) Execute the query and return the filtered Collection.
java.lang.Object	executeWithMap(java.util.Map parm1) Execute the query and return the filtered Collection.
boolean	getIgnoreCache() Returns always TRUE since cache is never accessed in query execution
PersistenceManager	getPersistenceManager() Get the PersistenceManager associated with this Query.
boolean	isPolymorphic() Return polymorphic feature of query execution.
void	setCandidates(java.util.Collection parm1) Set the candidate Collection to query.
void	setCandidates(Extent parm1) Set the candidate Extent to query.
void	setClass(java.lang.Class iClass) Set the class of the candidate instances of the query.
void	setClass(java.lang.String iClassName)
void	setDatabase(java.lang.String iUrl)
void	setFilter(java.lang.String iFilter) Set the filter for the query.
void	setIgnoreCache(boolean iValue) Set the ignoreCache option.
void	setOrdering(java.lang.String parm1) Set the ordering specification for the result Collection.
void	setPolymorphic(boolean iValue)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

oQuery

public oQuery(oPersistenceManager iManager)

Create an empty query passing the PersistenceManager associated.

Parameters:

iManager -

Method Detail

compile

public void compile()

Compile the query.

Specified by:

compile in interface Query

declareImports

public void declareImports(java.lang.String parm1)

Description copied from interface: Query

Set the import statements to be used to identify the fully qualified name of variables or parameters. Parameters and unbound variables might come from a different class from the candidate class, and the names need to be declared in an import statement to eliminate ambiguity. Import statements are specified as a String with semicolon-separated statements.

The String parameter to this method follows the syntax of the import statement of the Java language.

Specified by:

declareImports in interface Query

Parameters:

parm1 - import statements separated by semicolons.

declareParameters

public void declareParameters(java.lang.String parm1)

Description copied from interface: Query

Declare the list of parameters query execution. The parameter declaration is a String containing one or more query parameter declarations separated with commas. Each parameter named in the parameter declaration must be bound to a value when the query is executed.

The String parameter to this method follows the syntax for formal parameters in the Java language.

Specified by:

declareParameters in interface Query

Parameters:

parm1 - the list of parameters separated by commas.

declareVariables

public void declareVariables(java.lang.String parm1)

Description copied from interface: Query

Declare the unbound variables to be used in the query. Variables might be used in the filter, and these variables must be declared with their type. The unbound variable declaration is a String containing one or more unbound variable declarations separated with semicolons. It follows the syntax for local variables in the Java language.

Specified by:

declareVariables in interface Query

Parameters:

parm1 - the variables separated by semicolons.

execute

public java.lang.Object execute()

Execute the query returning a collection with results or the persistent object if the query returns only one object.

Specified by:

execute in interface Query

Returns:

A oResultSet instance containing the collection of objects returned by query execution ot the persistent object directly.

See Also:

#oResultSet

execute

public java.lang.Object execute(java.lang.Object parm1)

Description copied from interface: Query

Execute the query and return the filtered Collection.

Specified by:

execute in interface Query

Parameters:

parm1 - the value of the first parameter declared.

Returns:

the filtered Collection.

See Also:

Query.executeWithArray(Object[] parameters)

execute

public java.lang.Object execute(java.lang.Object parm1,
                                java.lang.Object parm2)

Description copied from interface: Query

Execute the query and return the filtered Collection.

Specified by:

execute in interface Query

Parameters:

parm1 - the value of the first parameter declared.

parm2 - the value of the second parameter declared.

Returns:

the filtered Collection.

See Also:

Query.executeWithArray(Object[] parameters)

execute

public java.lang.Object execute(java.lang.Object parm1,
                                java.lang.Object parm2,
                                java.lang.Object parm3)

Description copied from interface: Query

Execute the query and return the filtered Collection.

Specified by:

execute in interface Query

Parameters:

parm1 - the value of the first parameter declared.

parm2 - the value of the second parameter declared.

parm3 - the value of the third parameter declared.

Returns:

the filtered Collection.

See Also:

Query.executeWithArray(Object[] parameters)

executeWithArray

public java.lang.Object executeWithArray(java.lang.Object[] parm1)

Description copied from interface: Query

Execute the query and return the filtered Collection.

The execution of the query obtains the values of the parameters and matches them against the declared parameters in order. The names of the declared parameters are ignored. The type of the declared parameters must match the type of the passed parameters, except that the passed parameters might need to be unwrapped to get their primitive values.

The filter, import, declared parameters, declared variables, and ordering statements are verified for consistency.

Each element in the candidate Collection is examined to see that it is assignment compatible to the Class of the query. It is then evaluated by the Boolean expression of the filter. The element passes the filter if there exist unique values for all variables for which the filter expression evaluates to true.

Specified by:

executeWithArray in interface Query

Parameters:

parm1 - the Object array with all of the parameters.

Returns:

the filtered Collection.

executeWithMap

public java.lang.Object executeWithMap(java.util.Map parm1)

Description copied from interface: Query

Execute the query and return the filtered Collection. The query is executed with the parameters set by the Map values. Each Map entry consists of a key which is the name of the parameter in the declareParameters method, and a value which is the value used in the execute method. The keys in the Map and the declared parameters must exactly match or a JDOUserException is thrown.

Specified by:

executeWithMap in interface Query

Parameters:

parm1 - the Map containing all of the parameters.

Returns:

the filtered Collection.

See Also:

Query.executeWithArray(Object[] parameters)

getIgnoreCache

public boolean getIgnoreCache()

Returns always TRUE since cache is never accessed in query execution

Specified by:

getIgnoreCache in interface Query

Returns:

always TRUE

See Also:

Query.setIgnoreCache(boolean)

isPolymorphic

public boolean isPolymorphic()

Return polymorphic feature of query execution. If true, then the query will be executed on all instance of candidate class and all sub-classes.

Returns:

true if is polymorphic, otherwise false

setPolymorphic

public void setPolymorphic(boolean iValue)

getPersistenceManager

public PersistenceManager getPersistenceManager()

Description copied from interface: Query

Get the PersistenceManager associated with this Query.

If this Query was restored from a serialized form, it has no PersistenceManager, and this method returns null.

Specified by:

getPersistenceManager in interface Query

Returns:

the PersistenceManager associated with this Query.

setCandidates

public void setCandidates(java.util.Collection parm1)

Description copied from interface: Query

Set the candidate Collection to query.

Specified by:

setCandidates in interface Query

Parameters:

parm1 - the candidate Collection.

setCandidates

public void setCandidates(Extent parm1)

Description copied from interface: Query

Set the candidate Extent to query.

Specified by:

setCandidates in interface Query

Parameters:

parm1 - the candidate Extent.

setDatabase

public void setDatabase(java.lang.String iUrl)

setClass

public void setClass(java.lang.Class iClass)

Description copied from interface: Query

Set the class of the candidate instances of the query.

The class specifies the class of the candidates of the query. Elements of the candidate collection that are of the specified class are filtered before being put into the result Collection.

Specified by:

setClass in interface Query

Parameters:

iClass - the Class of the candidate instances.

setClass

public void setClass(java.lang.String iClassName)

setFilter

public void setFilter(java.lang.String iFilter)

Description copied from interface: Query

Set the filter for the query.

The filter specification is a String containing a Boolean expression that is to be evaluated for each of the instances in the candidate collection. If the filter is not specified, then it defaults to "true", which has the effect of filtering the input Collection only for class type.

An element of the candidate collection is returned in the result if:

• it is assignment compatible to the candidate Class of the Query; and
• for all variables there exists a value for which the filter expression evaluates to true.

The user may denote uniqueness in the filter expression by explicitly declaring an expression (for example, e1 != e2).

Rules for constructing valid expressions follow the Java language, except for these differences:

• Equality and ordering comparisons between primitives and instances of wrapper classes are valid.
• Equality and ordering comparisons of Date fields and Date parameters are valid.
• White space (non-printing characters space, tab, carriage return, and line feed) is a separator and is otherwise ignored.
• The assignment operators =, +=, etc. and pre- and post-increment and -decrement are not supported. Therefore, there are no side effects from evaluation of any expressions.
• Methods, including object construction, are not supported, except for Collection.contains(Object o), Collection.isEmpty(), String.startsWith(String s), and String.endsWith(String e). Implementations might choose to support non-mutating method calls as non-standard extensions.
• Navigation through a null-valued field, which would throw NullPointerException, is treated as if the filter expression returned false for the evaluation of the current set of variable values. Other values for variables might still qualify the candidate instance for inclusion in the result set.
• Navigation through multi-valued fields (Collection types) is specified using a variable declaration and the Collection.contains(Object o) method.

Identifiers in the expression are considered to be in the name space of the specified class, with the addition of declared imports, parameters and variables. As in the Java language, this is a reserved word which means the element of the collection being evaluated.

Navigation through single-valued fields is specified by the Java language syntax of field_name.field_name....field_name.

A JDO implementation is allowed to reorder the filter expression for optimization purposes.

Specified by:

setFilter in interface Query

Parameters:

iFilter - the query filter.

setIgnoreCache

public void setIgnoreCache(boolean iValue)

Description copied from interface: Query

Set the ignoreCache option. The default value for this option was set by the PersistenceManagerFactory or the PersistenceManager used to create this Query. The ignoreCache option setting specifies whether the query should execute entirely in the back end, instead of in the cache. If this flag is set to true, an implementation might be able to optimize the query execution by ignoring changed values in the cache. For optimistic transactions, this can dramatically improve query response times.

Specified by:

setIgnoreCache in interface Query

Parameters:

iValue - the setting of the ignoreCache option.

setOrdering

public void setOrdering(java.lang.String parm1)

Description copied from interface: Query

Set the ordering specification for the result Collection. The ordering specification is a String containing one or more ordering declarations separated by commas.

Each ordering declaration is the name of the field on which to order the results followed by one of the following words: "ascending" or "descending".

The field must be declared in the candidate class or must be a navigation expression starting with a field in the candidate class.

Valid field types are primitive types except boolean; wrapper types except Boolean; BigDecimal; BigInteger; String; and Date.

Specified by:

setOrdering in interface Query

Parameters:

parm1 - the ordering specification.

close

public void close(java.lang.Object p0)

Description copied from interface: Query

Close a query result and release any resources associated with it. The parameter is the return from execute(...) and might have iterators open on it. Iterators associated with the query result are invalidated: they return false to hasNext() and throw NoSuchElementException to next().

Specified by:

close in interface Query

Parameters:

p0 - the result of execute(...) on this Query instance.

closeAll

public void closeAll()

Description copied from interface: Query

Close all query results associated with this Query instance, and release all resources associated with them. The query results might have iterators open on them. Iterators associated with the query results are invalidated: they return false to hasNext() and throw NoSuchElementException to next().

Specified by:

closeAll in interface Query