MySQL Bugs: #13871: PK_NAME metadata object returns null value

Bug #13871	PK_NAME metadata object returns null value
Submitted:	9 Oct 2005 12:12	Modified:	8 Nov 2005 14:15
Reporter:	Hamza Essounni	Email Updates:
Status:	Won't fix	Impact on me:	None
Category:	MaxDB	Severity:	S1 (Critical)
Version:	7.6	OS:	Windows (Windows2000 SP4)
Assigned to:	Ulf Wendel	CPU Architecture:	Any

Description:
When trying to get the PK_NAME attribute value from the metadata catalog using a jdbc interface or sqlStudio nothing is returned,althought  a primary key constraint was explicitly defined in the table.
It seems that this is a problem related to the database catalog it self not to the jdbc driver.

How to repeat:
--first create the table
create table USERS(
login varchar(25) constraint pk_users primary key,
password varchar(25))
//
--or
create table USERS(
login varchar(25) not null,
password varchar(25),
constraint pk_users primary key(login))
//

--"pk_users" is what should be returned in both cases

public class SapMetaData(
   String db_name="demodb";
    String user="dbadmin";
    String pwd ="dbadmin";
public static void main(String[] arg){
try{
 Class.forName("com.sap.dbtech.jdbc.DriverSapDB");
String url = "jdbc:sapdb:///"+db_name;
con=DriverManager.getConnection(url,user,pwd);
  ResultSet rs=con.getMetaData().getPrimaryKeys(con.getCatalog(),"DEMO","USERS");
   while(rs.next()){
           System.out.println("the TABLE_NAME is "+rs.getString("TABLE_NAME"));
            System.out.println("the COLUMN_NAME is "+rs.getString"COLUMN_NAME"));
           System.out.println("the PK_NAME is "+rs.getString("PK_NAME"));
           System.out.println("the KEY_SEQUENCE is "+rs.getString("KEY_SEQ"));
                     
          }
}
}
}
--this is what we get
the TABLE_NAME is USERS
the COLUMN_NAME is LOGIN
the PK_NAME is null
the KEY_SEQUENCE is 1

Suggested fix:
make the value of the PK_NAME metadata attribute the some as the the primary key constraint name defined in the database schema.

Thanks for your report. I've forwarded the problem to the responsible developers.

Regards,
Ulf

Hamza,

the developers are checking if MaxDB stores the "name of a primary key" in any public available system table. If this is not the case, then the JDBC driver can't return a name at all.

Regards,
Ulf

Hi,

this is a missing feature. MaxDB does not store PK names anywhere. That's why the JDBC driver can't return any names.

It won't be fixed in the near future.

Regards,
Ulf