Is This Possible

[bbeshlian]

Hello,

Can a relationship be built between a Formula type Primary Key in one table and a Formula type Foreign Key in another table?

Thanks.

[Aether]

Hello @bbeshlian,

No, it cannot. Using a formula DataType to set up a relationship between two tables is not possible.

You can check this documentation for more information:

https://howto.caspio.com/tables-and-views/relationships/creating-and-managing-relationships/

I hope this information is helpful

~WatashiwaJin~

[SunakoChan]

Hi @bbeshlian,

Here are the DataTypes that are compatible with each other.

Data Type	Description	Examples	Conversion Compatibility
Text (255)	Used for a string of text of up to 255 alphanumeric characters and/or symbols. This data type is the most common data type and yields the fastest performance in searches.   You can also use this data type for numeric characters that are not used as numbers in calculations or formatting—such as phone numbers, zip codes, and social security numbers. Not doing so impacts formatting and prevents proper sorting by this field.	First_Name, State, Phone, Zip_Code	Text (64000)   File (provided that the text field contains proper file paths)
Text (64000)	Used for a long string of text of up to 64,000 alphanumeric characters and/or symbols.   Use this data type for description fields or other lengthy text data. Otherwise, use Text (255), which performs much faster.	Description, Comments	Text (255) (longer strings are truncated)   File (provided that the text field contains proper file paths)
Number	Used for decimal numbers.	Weight, height, area, percentage values	Text (255)   Text (64000) Integer (decimal values are truncated) Currency (allows up to four decimal points)
Integer	Used for numbers that do not have a decimal point, can be used as IDs and in relationships.	Age, number of children	Text (255)   Text (64000) Number Currency
Currency	Used for money fields in any currency.	Price, Salary	Text (255)   Text (64000) Integer (decimal values are truncated)
Autonumber	An automatically-assigned ID field. The value is incremented by 1 for each new record and cannot be changed except by resetting it for the entire table.	Customer_ID, Record_ID	Text (255)   Text (64000) Number Integer Currency
Prefixed Autonumber	An automatically-assigned ID field with the ability to add a prefix.   Use the Options area to configure the prefix and number format of the ID code to be generated.	Customer_ID, Record_ID	Text (255)   Text (64000)
Random ID	A unique system-generated random ID field with the ability to add a prefix as well as define the length and composition of characters, digits, or both.   Use the Options area to configure the prefix and number of characters the ID code should contain. You can also specify whether to include alphabet characters only, numbers only, or both (alphanumeric).	Customer_ID, Record_ID	Text (255)   Text (64000)
GUID	A system-generated and globally-unique identifier value, typically used as a complex unique value.	Customer_ID, Record_ID	Text (255)   Text (64000)
Date/Time	Used for date and time data.   DataPages automatically display a calendar picker for date/time fields. ‘Precision’ is specified in the DataPage and is used to configure which part of the date or time part is used. Use the Options area to specify whether or not to allow blank values in this field.	Followup_Date, Date_of_Birth	Text (255)   Text (64000) Timestamp
Yes/No	Used for fields that allow only two possible values: yes or no (true or false).   By default a Yes/No input field appears as a checkbox in forms.	Active_User, Requested_Newsletter, Published	Text (255)   Text (64000) Number
File	Used to associate files with a record.   File fields allow your app users to upload files using a web form. Files are stored in your database and can be used in DataPages. Files can also be accessed in the Files area of All Assets, organized in a file folder structure.	Profile_Photo, Resume, Contract	Text (255) may be truncated   Text (64000)
Password	Used for storing user passwords.   The value of this field is always encrypted and cannot be seen in Datasheet or DataPages.	Password	None
Timestamp	A timestamp is a type of smart field that automatically records the date and time when a record is submitted and/or updated.   Use the Options area to configure the time zone and the general behavior of the timestamp.	Date_Submitted, Date_Updated	Text (255)   Text (64000) Date/Time
Formula	A formula field is a calculated value based on other fields of the record and various math, date/time, text and other expressions.   Use the Options area to create the formula.	Full_Name, Profit, Shift_Duration	The data type of a formula field depends on its expression and return value and follows the conversion compatibility for that data type. After any conversion, the computed values are replaced with static values.
List	A special data type for storing a collection of strings, numbers or dates in a single field.	Allergies, Pizza_Toppings	None

You may also check this HowTo documentation: https://howto.caspio.com/tables-and-views/data-types/ .

I hope this helps.

[Glitch]

Technically speaking, in order to create a Unique Formula Field inside your table, one of the fields inside the Formula field SHOULD be unique. Otherwise, possible chances are - there could have been duplicates for the value.

If you want to create a relationship from one table to another, I suggest that you use the unique field instead. 

I hope this helps.

[DefinitelyNot31337]

Quick answer as to if it is possible to create a relationship with a formula field is No. This is because Formula fields are not actually stored or "persisted", AFAIK. If Caspio allows this as a feature in the future, I bet it's more or less similar to the workaround provided below (happening behind the scenes)

 

The closest way to do so is to create a Text Field to permanently store the Formula Field's information. Specify a trigger to write values to this text field where in (OnInsert, OnUpdate) Update #inserted SET TextField = FormulaField.

Then, you may treat the TextField as the actual foreign key.

[bbeshlian]

Here is the trigger I built. It validates. However when I go to update/insert I get the error stating the Key field is required. 

Here are the Editing options for the Results page

Thoughts? Thanks.

[Queso]

Hi, if you are establishing a relationship between tables, you have to follow compatible data types. Please see the following screenshot for Relationship Compatibility: