JPA : query is not cached because it generates multiple SQL statements - jpa

Question

I am getting so many warning message log.
Query is not cached because it generates multiple SQL statements. A query can be cached only when it corresponds to a single SQL statement
Runtime W CWWJP9991W: openjpa.Runtime: Warn: Query "SELECT ent FROM Event ent ORDER BY ent.name" is removed from cache excluded permanently.
Query "SELECT ent FROM Event ent ORDER BY ent.name" is not cached because it generates multiple SQL statements.
A query can be cached only when it corresponds to a single SQL statement. .
#Entity
#Table(name="EVENT")
public class Event {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="GEN_ID")
private Long genId;
#Column(name="NAME")
private String name;
#Column(name="LOCATION")
private String location;
#Column(name="EVENT_ID")
private String eventID;
#Temporal(TemporalType.TIMESTAMP)
#Column(name ="CREATION_DATE",nullable=false)
private Date creationDate;
#Temporal(TemporalType.TIMESTAMP)
#Column(name ="START_DATE")
private Date startDate;
#Temporal(TemporalType.TIMESTAMP)
#Column(name ="END_DATE")
private Date endDate;
#Column(name="STATUS")
private String status;
#Column(name="LANGUAGE")
private String language;
#Column(name="ACTIVE")
private Boolean active;
#Column(name="ACCESS_CONTROL")
private Boolean accessControl;
#Column(name="FILE_NAME")
private String fileName;
}