error no master data blocks are available

问题

I try create project but I have get to proplem in form builder when I click right and chose data block then chose table and click in add realshenshep I get these error said 'error no master data blocks are available' Please help me I am waiting to reply me Thanx

回答1:

If you want the Wizard to create relationship between master and detail block, underlying tables have to be related - master table has to have a primary key, and it has to be referenced by detail table's foreign key.

Forms is capable of detecting that and, if it exists, can create the relationship.

Otherwise, if there's no such a relation between those tables, you'll have to create it manually.

[EDIT]

How to create a foreign key?

SQL> create table master
  2    (id    number,
  3     name  varchar2(20));

Table created.

SQL> create table detail
  2    (id   number,
  3     idm  number,
  4     datum date
  5    );

Table created.

SQL> -- create a primary key on the master table
SQL> alter table master add constraint pk_mas primary key (id);

Table altered.

SQL> -- create a foreign key on the detail table
SQL> alter table detail add constraint fk_det_mas foreign key (idm)
  2    references master (id);

Table altered.

SQL>

As of manually creating a relationship: put the join condition in there, such as

detail.idm = master.id

来源：https://stackoverflow.com/questions/55249375/error-no-master-data-blocks-are-available