com.espertech.esper.client.soda
Class EPStatementObjectModel

java.lang.Object
  extended by com.espertech.esper.client.soda.EPStatementObjectModel
All Implemented Interfaces:
Serializable

public class EPStatementObjectModel
extends Object
implements Serializable

Object model of an EPL statement.

Applications can create an object model by instantiating this class and then setting the various clauses. When done, use EPAdministrator to create a statement from the model.

Alternativly, a given textual EPL can be compiled into an object model representation via the compile method on EPAdministrator.

Use the toEPL method to generate a textual EPL from an object model.

Minimally, and EPL statement consists of the select-clause and the where-clause. These are represented by SelectClause and FromClause respectively.

Here is a short example that create a simple EPL statement such as "select page, responseTime from PageLoad" :

 EPStatementObjectModel model = new EPStatementObjectModel();
 model.setSelectClause(SelectClause.create("page", "responseTime"));
 model.setFromClause(FromClause.create(FilterStream.create("PageLoad")));
 

The select-clause and from-clause must be set for the statement object model to be useable by the administrative API. All other clauses a optional.

Please see the documentation set for further examples.

See Also:
Serialized Form

Constructor Summary
EPStatementObjectModel()
          Ctor.
 
Method Summary
 CreateVariableClause getCreateVariable()
          Returns the create-variable clause if this is a statement creating a variable, or null if not.
 CreateWindowClause getCreateWindow()
          Returns the create-window clause for creating named windows, or null if this statement does not create a named window.
 FromClause getFromClause()
          Return the from-clause.
 GroupByClause getGroupByClause()
          Return the group-by-clause, or null to indicate that the clause is absent.
 Expression getHavingClause()
          Return the having-clause, or null to indicate that the clause is absent.
 InsertIntoClause getInsertInto()
          Return the insert-into-clause, or null to indicate that the clause is absent.
 OnClause getOnExpr()
          Returns the on-delete clause for deleting from named windows, or null if this statement does not delete from a named window
 OrderByClause getOrderByClause()
          Return the order-by-clause, or null to indicate that the clause is absent.
 OutputLimitClause getOutputLimitClause()
          Return the output-rate-limiting-clause, or null to indicate that the clause is absent.
 SelectClause getSelectClause()
          Return the select-clause.
 Expression getWhereClause()
          Return the where-clause, or null to indicate that the clause is absent.
 void setCreateVariable(CreateVariableClause createVariable)
          Sets the create-variable clause if this is a statement creating a variable, or null if not.
 void setCreateWindow(CreateWindowClause createWindow)
          Sets the create-window clause for creating named windows, or null if this statement does not create a named window.
 EPStatementObjectModel setFromClause(FromClause fromClause)
          Specify a from-clause.
 EPStatementObjectModel setGroupByClause(GroupByClause groupByClause)
          Specify a group-by-clause.
 EPStatementObjectModel setHavingClause(Expression havingClause)
          Specify a having-clause.
 EPStatementObjectModel setInsertInto(InsertIntoClause insertInto)
          Specify an insert-into-clause.
 void setOnExpr(OnClause onExpr)
          Sets the on-delete or on-select clause for selecting or deleting from named windows, or null if this statement does not on-select or on-delete from a named window
 EPStatementObjectModel setOrderByClause(OrderByClause orderByClause)
          Specify an order-by-clause.
 EPStatementObjectModel setOutputLimitClause(OutputLimitClause outputLimitClause)
          Specify an output-rate-limiting-clause.
 EPStatementObjectModel setSelectClause(SelectClause selectClause)
          Specify a select-clause.
 EPStatementObjectModel setWhereClause(Expression whereClause)
          Specify a where-clause.
 String toEPL()
          Renders the object model in it's EPL syntax textual representation.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

EPStatementObjectModel

public EPStatementObjectModel()
Ctor.

Method Detail

setInsertInto

public EPStatementObjectModel setInsertInto(InsertIntoClause insertInto)
Specify an insert-into-clause.

Parameters:
insertInto - specifies the insert-into-clause, or null to indicate that the clause is absent
Returns:
model

getInsertInto

public InsertIntoClause getInsertInto()
Return the insert-into-clause, or null to indicate that the clause is absent.

Returns:
specification of the insert-into-clause, or null if none present

setSelectClause

public EPStatementObjectModel setSelectClause(SelectClause selectClause)
Specify a select-clause.

Parameters:
selectClause - specifies the select-clause, the select-clause cannot be null and must be set
Returns:
model

getSelectClause

public SelectClause getSelectClause()
Return the select-clause.

Returns:
specification of the select-clause

setFromClause

public EPStatementObjectModel setFromClause(FromClause fromClause)
Specify a from-clause.

Parameters:
fromClause - specifies the from-clause, the from-clause cannot be null and must be set
Returns:
model

getWhereClause

public Expression getWhereClause()
Return the where-clause, or null to indicate that the clause is absent.

Returns:
specification of the where-clause, or null if none present

setWhereClause

public EPStatementObjectModel setWhereClause(Expression whereClause)
Specify a where-clause.

Parameters:
whereClause - specifies the where-clause, which is optional and can be null
Returns:
model

getFromClause

public FromClause getFromClause()
Return the from-clause.

Returns:
specification of the from-clause

getGroupByClause

public GroupByClause getGroupByClause()
Return the group-by-clause, or null to indicate that the clause is absent.

Returns:
specification of the group-by-clause, or null if none present

setGroupByClause

public EPStatementObjectModel setGroupByClause(GroupByClause groupByClause)
Specify a group-by-clause.

Parameters:
groupByClause - specifies the group-by-clause, which is optional and can be null
Returns:
model

getHavingClause

public Expression getHavingClause()
Return the having-clause, or null to indicate that the clause is absent.

Returns:
specification of the having-clause, or null if none present

setHavingClause

public EPStatementObjectModel setHavingClause(Expression havingClause)
Specify a having-clause.

Parameters:
havingClause - specifies the having-clause, which is optional and can be null
Returns:
model

getOrderByClause

public OrderByClause getOrderByClause()
Return the order-by-clause, or null to indicate that the clause is absent.

Returns:
specification of the order-by-clause, or null if none present

setOrderByClause

public EPStatementObjectModel setOrderByClause(OrderByClause orderByClause)
Specify an order-by-clause.

Parameters:
orderByClause - specifies the order-by-clause, which is optional and can be null
Returns:
model

getOutputLimitClause

public OutputLimitClause getOutputLimitClause()
Return the output-rate-limiting-clause, or null to indicate that the clause is absent.

Returns:
specification of the output-rate-limiting-clause, or null if none present

setOutputLimitClause

public EPStatementObjectModel setOutputLimitClause(OutputLimitClause outputLimitClause)
Specify an output-rate-limiting-clause.

Parameters:
outputLimitClause - specifies the output-rate-limiting-clause, which is optional and can be null
Returns:
model

toEPL

public String toEPL()
Renders the object model in it's EPL syntax textual representation.

Returns:
EPL representing the statement object model
Throws:
IllegalStateException - if required clauses do not exist

getCreateWindow

public CreateWindowClause getCreateWindow()
Returns the create-window clause for creating named windows, or null if this statement does not create a named window.

Returns:
named window creation clause

setCreateWindow

public void setCreateWindow(CreateWindowClause createWindow)
Sets the create-window clause for creating named windows, or null if this statement does not create a named window.

Parameters:
createWindow - is the named window creation clause

getOnExpr

public OnClause getOnExpr()
Returns the on-delete clause for deleting from named windows, or null if this statement does not delete from a named window

Returns:
on delete clause

setOnExpr

public void setOnExpr(OnClause onExpr)
Sets the on-delete or on-select clause for selecting or deleting from named windows, or null if this statement does not on-select or on-delete from a named window

Parameters:
onExpr - is the on-expression (on-select and on-delete) clause to set

getCreateVariable

public CreateVariableClause getCreateVariable()
Returns the create-variable clause if this is a statement creating a variable, or null if not.

Returns:
create-variable clause

setCreateVariable

public void setCreateVariable(CreateVariableClause createVariable)
Sets the create-variable clause if this is a statement creating a variable, or null if not.

Parameters:
createVariable - create-variable clause

© 2007 EsperTech Inc.
All rights reserved.
Visit us at espertech.com