How can I search for all tickets that have issue links to another project?

[Joy RK]

Trying to create a JQL to search for all tickets that have an issue link to another project.
e.g AB-1234 is related to BC-6789

find all cases where project = AB and issue links contain BC-

[Joy RK · Accepted solution]

I was able to use the following JQL structure to achieve my goal successfully.

project = AB and issueFunction not in linkedIssuesOf("project=CD") ORDER BY created  DESC

[Muhammad Ramzan_Atlassian Certified Master_]

As mentioned by Paul, its not possible naively, I am using  JQL Search Extensions for Jira & reports.

I found following query can get the required results which you want.

Will all issues which are linked or links project JQL

issue in linkedByIssueProject("JQL")

Find issues which link at least one issue from project JQL. 

issue in links("project = JQL")

Find issues which "blocks" at least one issue from project JQL. 

issue in links("blocks", "project = JQL")

Documentation link here

https://jqlsearchextensions.atlassian.net/wiki/spaces/SEARCH/pages/30497099/JQL+Reference+Server#JQLReference(Server)-LinkedByIssueProject

[Paul Mata]

@Joy RK, see Andy Heinzer's response from August 16, 2019 in the thread for this question. Simply put, there is currently no way to do that natively in Jira.

There are third party plugins (like ScriptRunner by Adaptavist) that extend the functionality of JQL and will allow you to find linked issues in other projects. See the thread on this question for information on a simple ScriptRunner query that should help you.