Calculated items based on external checks

[BernyeCZ]

I am working with Zabbix 3.0 LTS. I monitor specific keys (limit and used count) from API (JSON) source throught external check with *.sh script. If I make own script for each key (curl + jq) (merk_cz_exp-hits.sh, merk_cz_exp-limit.sh) and than specify new calculated item for percentual count based on used amount. Everything woks perfect.

calculated item: 100*last(merk_cz_exp-hits.sh)/last(merk_cz_exp-limit.sh) - work perfect

Now I try to change keys for limit and used items to use same script with parameters for jq:

Item1:
type: external check
key: merk.sh["cz","details_limit"]
information type: number (unsigned)

Item2:
type: external check
key: merk.sh["cz","details_hits"]
information type: number (unsigned)

Item3:
type: calculated
formula: last(merk.sh["cz","details_hits"])/(merk.sh["cz","details_limit"])
information type: number (float)


Item1 and Item2 work perfect

Item3 report me back "Not supported" (Incorrect function 'last' expression. Check expression part starting from: "details_hits").

When I try modify Item3 to (merk.sh["cz","details_hits"])/(merk.sh["cz","details_limit"]) zabbix report me back "Not supported" (Incorrect function expression: merk.sh["cz","details_hits"])/(merk.sh["cz","details_limit"]))

Can anyone explain me, where I make a mistake.

Thanks

[BernyeCZ]

I have an answer.

Good formula is: last("merk.sh["cz","details_hits"]")/last("merk.sh["cz","details_limitq"]")

I forget to add \ inside (" ")