Mapping String attribute in EntityBean to CHAR(size) in DB

[henning1]

I have a composite PK class that consists of {int, int, String, String}.
Both attributes of type String are mapped to CHAR(size) instead of VARCHAR2(size) in an Oracle DB.

My Problem:
The EntityManager's
find(Class entityClass, Object primaryKey) method returns null instead of an EntityBean.

It all works if I handcode my EJBQL and insert the two Strings with trailing white spaces to match the size of the CHAR-Colums in the DB.

This is somewhat strange because a SQL select statement works fine without supplying trailing white spaces in the where clause.

Any suggestions other than changing to VARCHAR2??

[andydale]

Hi,

Could you not just annotate the getter/variable with something like so:

@Column(columnDefinition="VARCHAR2(<size>)")

Cheers

Andy

[henning1]

The 'columDefinition' just helps the PersistenceProvider to set up the right DDL for the Table when you set it up to create the Tables at Deployment
:-(
But thanks

[chris1]

I have the same problem. There is a char(3) column in my mysql database I cannot change. What's the right java type I can map this to in my @Entity?

char[], Character[] etc/ gives me an "Varchar expected" exception.

Thanks,

Chris

[fheldt]

I fixed this behavior with a simple UserType. Just annotate

import org.hibernate.annotations.Type;
...
@Column(name = "XYZ")
@Type(type = "usertype.TrimmedStringType")
private String xyz;

The TrimmedStringType source is like this:

package usertype;

import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

import org.hibernate.HibernateException;
import org.hibernate.usertype.UserType;


public class TrimmedStringType implements UserType {

 private static final int[] SQL_TYPES = { Types.CHAR };

 public int[] sqlTypes() {
 return SQL_TYPES;
 }

 public Class returnedClass() {
 return String.class;
 }

 public Object assemble(Serializable cached, Object owner) throws HibernateException {
 return cached;
 }

 public Object deepCopy(Object obj) throws HibernateException {
 if (obj == null) {
 return null;
 }
 return new String((String) obj);
 }

 public Serializable disassemble(Object value) throws HibernateException {
 return (Serializable) value;
 }

 public boolean equals(Object x, Object y) throws HibernateException {
 return (x == y) || (x != null && y != null && (x.equals(y)));
 }

 public int hashCode(Object x) throws HibernateException {
 return x.hashCode();
 }

 public boolean isMutable() {
 return false;
 }

 public Object nullSafeGet(ResultSet rs, String[] names, Object obj) throws HibernateException, SQLException {
 String val = rs.getString(names[0]);
 return val != null ? val.trim() : null;
 }

 public void nullSafeSet(PreparedStatement pstmt, Object obj, int i) throws HibernateException, SQLException {
 pstmt.setString(i, (String)obj);
 }

 public Object replace(Object original, Object target, Object owner) throws HibernateException {
 return original;
 }
}

I hope this helps.

[chris1]

Thanks a lot! That worked for my char-datatype.

Do you have an idea how to deal with MEDIUMTEXT as (mysql) database type? What's the best java.sql.Type I can use for it?

Thanks,

Chris

[chris1]

Ok, this was an easy one @Column(length = 100000) did the trick.

Thanks!

Chris