Jira Structure: How to use aggregate function for issue links?

[Diana]

I'm try to add a formula column that will show a red X icon if the parent issue is blocked by a child issue via the issue link name.

Example:

Parent Issue - X
-Child issue 1 - done
-Child issue 2 - is not done and has link name "blocks"

I created a Formula column (if there's more than 1 blocking issue, show icon. If not, icon does not show: 

IF (SUM{aggBlocked} > 0, "(x)", "")

and the variable "aggBlocked" is another Formula that counts how many incomplete linked issues using "blocks":

IF (statuscategory != Done && issuelink.name = "blocks", 1, 0)

But the icon will not show. Am I using the issuelink property incorrectly?

[Diana · Accepted solution]

figured it out. Use the "Query Match" to map the variable, not Formula, and use JQL query type.

this query does not count the parent issue type, it only looks for the child issues using "blocks" link. if the child is rejected, it doesn't count. if the child issue is unresolved and using "blocks" link, it's counted

project=ABC and issuetype != parentIssueType and status != reject 
and issuefunction in hasLinkType("blocks") 
and issufunction in linkedissuesof("resolution is empty","blocks")