org.objectquery

Class QueryEngine<S>

java.lang.Object

org.objectquery.QueryEngine<S>

public abstract class QueryEngine<S>
extends Object

Constructor Summary

Constructors

Constructor and Description
QueryEngine()

Method Summary

Methods

Modifier and Type	Method and Description
static <T> QueryEngine<T>	defaultInstance() Create an new instance of query engine for the engine implementation present in the classpath.
abstract int	execute(DeleteQuery<?> dq, S engineSession) Execute a delete and return the number of deleted records.
abstract boolean	execute(InsertQuery<?> ip, S engineSession) Execute an insert usage example: QueryEngine engine = ...
abstract <RET extends List<?>> RET	execute(SelectQuery<?> query, S engineSession) Execute a select and return a list of result.
abstract int	execute(UpdateQuery<?> query, S engineSession) Execute an update usage example: QueryEngine engine = ...
static <T> QueryEngine<T>	instance(Class<T> sessionType) Create a new instance of the query engine for the specified session type.
<T> DeleteQuery<T>	newDelete(Class<T> target) Create a new delete query on the specified target.
<T> InsertQuery<T>	newInsert(Class<T> target) Create a new Insert query on the specified target.
<T> SelectQuery<T>	newSelect(Class<T> target) Create a new select query on the specified target usage example: QueryEngine<YourSession> engine = ....
<T> UpdateQuery<T>	newUpdate(Class<T> target) Create a new update query on the specified target.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryEngine

public QueryEngine()

Method Detail

instance

public static <T> QueryEngine<T> instance(Class<T> sessionType)

Create a new instance of the query engine for the specified session type. the instance created is state-less and multi-threading safe, reuse it.

Parameters:

sessionType - the session type used for find the query engine.

Returns:

a new instance of the query engine.

defaultInstance

public static <T> QueryEngine<T> defaultInstance()

Create an new instance of query engine for the engine implementation present in the classpath. the instance created is state-less and multi-threading safe, reuse it.

Returns:

the new instance.

newSelect

public <T> SelectQuery<T> newSelect(Class<T> target)

Create a new select query on the specified target usage example: QueryEngine<YourSession> engine = .... SelectQuery<Persongt; select = engine.newSelect(Person.class); Person target =select.target(); select.prj(target.getName()); select.prj(target.getSurname()); select.eq(target.getName(),"expected name");

Parameters:

target -

Returns:

new select query.

newDelete

public <T> DeleteQuery<T> newDelete(Class<T> target)

Create a new delete query on the specified target. usage example: QueryEngine<YourSessiongt; engine = .... DeleteQuery<Persongt; delete = engine.newDelete(Person.class); Person target =delete.target(); delete.eq(target.getName(),"expected name");

Parameters:

target -

Returns:

new delete query.

newUpdate

public <T> UpdateQuery<T> newUpdate(Class<T> target)

Create a new update query on the specified target. usage example: QueryEngine<YourSessiongt; engine = .... UpdateQuery<Persongt; update = engine.newUpdate(Person.class); Person target =update.target(); update.set(target.getName(),"new name"); update.eq(target.getName(),"expected name");

Parameters:

target -

Returns:

new update query.

newInsert

public <T> InsertQuery<T> newInsert(Class<T> target)

Create a new Insert query on the specified target. usage example: QueryEngine<YourSessiongt; engine = .... InserQuery<Persongt; insert = engine.newInsert(Person.class); Person target =insert.target(); insert.set(target.getName(),"the name"); insert.set(target.getSurname(),"the surname");

Parameters:

target -

Returns:

new insert query.

execute

public abstract <RET extends List<?>> RET execute(SelectQuery<?> query,
                                S engineSession)

Execute a select and return a list of result. usage example: QueryEngine engine = ... SelectQuery select = ... Person target = select.target(); select.eq(target.getName(),"expected name"); List

Parameters:

query - to execute

engineSession - current implementation session

Returns:

the result of the select

execute

public abstract int execute(DeleteQuery<?> dq,
          S engineSession)

Execute a delete and return the number of deleted records. usage example: QueryEngine engine = ... DeleteQuery delete = ... Person target = delete.target(); delete.eq(target.getName(),"expected name"); engine.execute(delete,yourSessionInstance);

Parameters:

query - to execute

engineSession - current implementation session

Returns:

the number of deleted record.

execute

public abstract boolean execute(InsertQuery<?> ip,
              S engineSession)

Execute an insert usage example: QueryEngine engine = ... InsertQuery insert = ... Person target = insert.target(); insert.set(target.getName(),"new name"); engine.execute(insert,yourSessionInstance);

Parameters:

query - to execute

engineSession - current implementation session

Returns:

true if the insert is executed correctly.

execute

public abstract int execute(UpdateQuery<?> query,
          S engineSession)

Execute an update usage example: QueryEngine engine = ... UpdateQuery update = ... Person target = update.target(); update.set(target.getName(),"new name"); update.eq(target.getName(),"current name"); engine.execute(update,yourSessionInstance);

Parameters:

query - to execute

engineSession - current implementation session

Returns:

the number of updated record