JPA COUNT with composite primary key query not working

Question

In my db, I have a table (Defaults), and when I generate an entity from table, I get these two classes:

@Entity public class Defaults implements Serializable {     private static final long serialVersionUID = 1L;     @EmbeddedId     protected DefaultsPK DefaultsPK;     @Column(name = "ERTEK")     private String ertek;      getter/setter... }  @Embeddable public class DefaultsPK implements Serializable {     @Basic(optional = false)     @Column(name = "VALUE_1")     private String value1;     @Basic(optional = false)     @Column(name = "TYPE")     private String type;     @Basic(optional = false)     @Column(name = "VALID_FROM")     @Temporal(TemporalType.TIMESTAMP)     private Date validFrom;     @Basic(optional = false)     @Column(name = "VALID_TO")     @Temporal(TemporalType.TIMESTAMP)     private Date validTo;      getter/setter... } 

That is why becaues the primary key is including the values. I want to count all the rows in the table, so I use this code:

String sql = "SELECT COUNT(d) FROM Defaults d"; Query q = em.createQuery(sql); long count = (long)q.getSingleResult(); 

But I am getting this error:

org.hibernate.exception.SQLGrammarException: could not execute query ... java.sql.SQLSyntaxErrorException: ORA-00907: The right expression is missing from the arithmetic expression 

What is the problem? The other count queries with other entities are working.

I am using hibernate.

Answer 1

Use count(d.ertek) or count(d.id) instead of count(d). This can be happen when you have composite primary key at your entity.