A linked relation column (formerly known as a reverse lookup column) serves as a complement to the relation column type, which allows you to pull in information from another table. Linked relations represent a bi-directional relationship between data in different tables and allow you to edit values from either side of the connection.

Linked relations are a very powerful, useful tool in Coda. They make it easier to connect and summarize data in related tables - such as Projects and Tasks. Once you get the hang of them, you might find yourself using linked relations all over your Coda docs!

To create a linked relation column, you first need to create a relation column (read all about those here).

For instance, let’s say you have two tables: a Tasks table and a Projects table. You’ve added a relation column to your Tasks table, which references the Projects table. For each row in the Tasks table, you use that relation column to indicate which Project goes with each task.

But now, you want to know which tasks are associated with each Project. In other words, you want to add a linked relation column to your Projects table. No problem - you can do this in a few clicks:

You’ll see that this newly created linked relation column automatically contains the data you’d expect to see - based on what you’ve added to the original relation column.

💡Tip: You can also add linked relation columns via the original relation column. Just go to the relation column in your Tasks table, right click on the column header, and find the Create linked relation column on Projects button. Click this and notice how that linked relation table is conveniently added to your Projects table.

Behind each linked relation column is a formula. This formula is automatically built when you create a linked relation column, so there’s no need to write or edit yourself. But if you’re curious, you can explore the formula by right clicking on the column header, then selecting Edit formula.

You’ll see there that linked relation columns are really just filter formulas. The formula takes the referenced table, and filters it to only show rows that contain references to the current row in your table. You can even click around on the various components of the formula, and the formula builder will provide some info to help you understand each piece. If you’re curious about Coda formulas, check out this article.

Just like all columns in Coda, the linked relation column has a number of settings that you can adjust based on your needs. To view these, right click on the column header, then select Linked relation options.

Here you’ll find:

When two-way editing is turned on for linked relation columns, this allows for a bidirectional relationship between the two linked tables. In other words, when this setting is on, you can make a change directly to the contents of the linked relation column, and this will automatically trigger a corresponding change to the original relation column.

By default, all new linked relation columns are created with this setting turned on. But sometimes you may want to only see the values from the source table - without the ability to edit them directly via the linked relation column. In that case, just head to the column settings and switch off the Allow two-way edits toggle.

Linked relation columns contain row references. The value of the display column is what’s shown. But when you hover over an item in a linked relation column you’ll see the full contents of the row, including the other columns. So what if you want to pull in one of these specific columns - something other than the display column - and show that in your table? No problem!

To do this, just follow these steps:

That’s it! That new column will now automatically populate based on which items are contained in the linked relation column for each row.

Yes - we recently updated the name of this feature to “linked relation.” With the rename, we also released a suite of improvements to make using this valuable feature even easier.

No - linked relation columns are a compliment to relation columns. You need to first create a relation column on one table, and then can create a linked relation column on the other table.

Linked relation columns contain row references. While they may look like they just contain text, the data is actually much richer. Each “bubble” (or “chip,” as we sometimes call it) within a linked relation column represents a row from another table. If you hover over the bubble, you’ll see a pop-up with the full contents of that row, including all the columns it contains.

Yes! The easiest way to do this is to use the linked relation column to add a related column. Check out the Add related columns section on this above.

A relation column represents the primary connection from Table A to Table B, whereas a linked relation represents the other side of the connection on Table B - and even lets you edit values back in Table A.

Another way to think of it: one relation column can have many linked relation columns connected to it, while a linked relation column is only connected to one relation column.