Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I think the problem is that you use <code>db.relationship()</code> in both <code>Person</code> and <code>WorkGroup</code> classes. Set it in one of them and use <code>backref</code> keyword argument to define the relationship on the other side.</p> <p>The other problem is that you've placed your foreign key in the wrong class. Since you want to have <a href="http://docs.sqlalchemy.org/en/rel_0_8/orm/relationships.html#many-to-one" rel="nofollow">many-to-one</a> relationship between <code>Person</code> and <code>WorkGroup</code> (many persons in one workgroup), you need to define <code>workgroup_id</code> FK in <code>Person</code> class and remove <code>members_id</code> (and <code>members</code>) from <code>WorkGroup</code>.</p> <p>After these changes I've got <code>CircularDependencyError</code> exception, most likely due to <code>prevPairings_id</code> FK <a href="http://docs.sqlalchemy.org/en/rel_0_8/orm/relationships.html#post-update" rel="nofollow">pointing to the same row</a>. Adding <code>post_update=True</code> to <code>prevPairings</code> relationship fixed that.</p> <p>So here are all the fixes you need to do for your code to work:</p> <pre><code>class Person(db.Model): # ... workgroup_id = db.Column(db.Integer, db.ForeignKey('workgroup.id')) # No need to set uselist=False, it will be determined automatically by # type of relationship (many-to-one in this case). workGroup = db.relationship("WorkGroup", backref='members') # ... prevPairings = db.relationship('Person', post_update=True) # ... class WorkGroup(db.Model): # ... # Removed members_id and members. # ... </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POFlask-SQLAlchemy Data Model Relationship Problems
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USAudrius Kažukauskas
    1. USAudrius Kažukauskas
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POFlask-SQLAlchemy Data Model Relationship Problems
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI will try that and report back. Regarding uselist=False, I'm not sure I understand the comment -- when I put it in then I seem to only be able to assign to None or an object, whereas if I leave it out than I only seem to be able to assign to [] (and perhaps other sequences like set()?)
      singulars
      1. PO
      1. USuser1677663
    2. COWhat I meant is that `relationship()` will figure out the type of relationship, e.g. that it's one-to-many, and on the side which represents 'one', it will set `uselist=False` automatically.
      singulars
      1. PO
      1. USAudrius Kažukauskas
    3. COAlas, that produced exactly the same stack trace as before. No joy yet.
      singulars
      1. PO
      1. USuser1677663
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload