Links between tables
A link records that a column in one table refers to a column in another: an order's customer_id pointing at a customer's id. Links describe the shape of your data, draw the graph view, and tell people and AI assistants how to join tables correctly.
Create a link
- Select a table on the canvas and click Add table link on the action bar. To start from a column instead, select its header and choose Link Column.
- In New Table Link, pick the other table.
- Pick a column on each side. When two columns look alike, Mycorr says "Looks like a match. Hit the link button to add your first pair."
- Click the link button to connect them.
The link appears in both tables' Table Links sections and as a line between them in the graph view.
Composite links
When one column on each side isn't enough to identify the related row, such as a country and a year, add more pairs to the same link. Together they make one composite link.
Links into a list
A link can also match a value against a List column: "Membership: the value occurs in the list". A membership pair makes the whole link, so it takes no further pairs.
Both tables must be in the model
You can only link tables that are both in the model you're working in. If the other table lives in another model, import it first; a link whose far end is missing says "Other endpoint lives in a different model. Import that table here to use this link."
Link health
Link Health checks whether a link's values actually line up. Open it from the link in the Table Links section. It reads both tables' released data and reports:
- How many rows on each side found a partner, how many are Unmatched, and how many have no key at all.
- Whether the link is one-to-one, one-to-many or many-to-many.
- With Show unmatched values, the exact values that found no partner.
Re-run audit checks again after you fix the data. Link health needs both tables to be released; before that it says "Link health is available once the table is released."
Who may create and delete a link
A link is a fact about two tables, so the right to create or delete one comes from the pair, never from one table alone.
The floor, for every link: you must be able to see both tables. If you can't, you can't create the link, delete it, or even see it, and the refusal tells you nothing about the table you can't see.
Above that floor:
| The pair | Who may create or delete |
|---|---|
| Two ordinary tables | Anyone who can edit either one |
| An ordinary table and a catalog table | Anyone who can edit the ordinary side |
| Two catalog tables | A catalog manager |
Importing a table gives you no link rights over it. Reading a published catalog table doesn't let you rewrite the catalog's links.
Links made for you
Some links aren't drawn by a person:
- An AI assistant connected through the MCP server can declare links for you. They are marked An agent declared this link. An assistant can delete only links that agents made for you; links people drew stay for people to remove.
- A recipe result's links come from the recipe that made it, marked This link comes from the recipe that made the result. They are rebuilt on every run and can't be edited by hand.
Links and moving a table
Moving a table to another organization can cut links, and the move dialog tells you how many before you confirm. A link is cut when its other end stays behind in an organization that could no longer see the table. Links to the destination organization, to the catalog or to a third organization survive, and a link from a table to itself moves with it.
Delete a link
Choose Delete table link on the link, or on a linked column's action bar, and confirm. Deleting a link can't be undone, but it touches no data: the tables and their rows stay exactly as they were.