Hello Wonseok,
I'm not sure if Tom responded to you or not I haven't received the email through the persistence mailing list yet.
typeName in TopLink is used as a place for a user to define definitions using generic database types (well mostly generic). Those types are then translated to a particular database type based on platform as you mentioned. This code is from the original implementation of the TopLink schema framework before ddl generation was written. I think the issue here is that columnDefinition is being stored in the typeName attribute. ColumnDefinition should really have its own property that overrides both type and typeName.
--Gordon
-----Original Message-----
From: Wonseok Kim [mailto:guruwons_at_gmail.com]
Sent: Friday, March 09, 2007 8:05 AM
To: persistence_at_glassfish.dev.java.net
Subject: Issue 1454 and FieldDefinition.typeName?
Hi Tom,
I'm looking into issue 1454 columnDefinition="TEXT" does not apply in table generation.
I'm fixing it, but I'm having problem in understanding the exact meaning of typeName field in FieldDefinition class.
DatabaseField has 'columnDefinition' field corresponding to user-defined column definition, and which is set to FieldDefinition's typeName(in this case FieldDefinition's type is null).
But as you see below code, the typeName is used to set its 'type' field and it is set to null!
TableDefinition.java
/**
* INTERNAL:
* Build the field types based on the given name read in from the file.
* Build the foriegn key constraints as well.
*/
protected void buildFieldTypes(AbstractSession session) {
buildForeignFieldTypes(session);
}
private void buildForeignFieldTypes(final AbstractSession session) {
Hashtable fieldTypes = session.getPlatform().getClassTypes();
FieldDefinition field = null;
// The ForeignKeyConstraint object is the newer way of doing things.
// We support FieldDefinition.getForeignKeyFieldName() due to backwards compatibility
// by converting it. To allow mixing both ways, we just add converted one to foreignKeys list.
for (Enumeration enumtr = getFields().elements(); enumtr.hasMoreElements();) {
field = (FieldDefinition)enumtr.nextElement();
if (field.getForeignKeyFieldName() != null) {
addForeignKeyConstraint(buildForeignKeyConstraint(field, session.getPlatform()));
}
//FROM HERE - It's removing typeName(columnDefinition)!
if ( field.getType() == null) {
field.setType((Class)fieldTypes.get(field.getTypeName()));
if (field.getType() != null) {
field.setTypeName(null);
}
}
}
}
This does not keep user-defined column definition. I thought the code is wrong and removed it. With some other changes, I could see the user-specified column definition is used properly.
But, I found that the code is used for another purpose in entity-persistence-tests. EPT is directly using FieldDefinition to generate tables like below.
FieldDefinition fieldSTREET = new FieldDefinition();
fieldSTREET.setName("STREET");
fieldSTREET.setTypeName("VARCHAR2");
fieldSTREET.setSize(60);
fieldSTREET.setSubSize(0);
fieldSTREET.setIsPrimaryKey(false);
fieldSTREET.setIsIdentity(false);
fieldSTREET.setUnique(false);
fieldSTREET.setShouldAllowNull(true);
table.addField(fieldSTREET);
As you know typeName "VARCHAR2" is only for Oracle, so it could not be used for other databases. The above type-related code is converting this 'typeName' to corresponding Java type which is converted to real database type later according to DatabasePlatform.
What is the exact meaning of 'typeName'?
If it is type definition analogous to @Column.columnDefinition, then tableCreators of EPT is abusing it - instead setType() should be used to be portable.
If it should be translated according to DatabasePlatform, it should not be used for @ Column.columnDefinition.
Could you explain?
Thanks
-Wonseok