Loop on JSON array in bash script and pull data through JQ - arrays

Question

i want to pull data from jSON file through jq in bash script. I have 50 plus SG objects in JSON .
here is an example of one SG . I want to print a VPC id and group id in one line and so on for another objects.
Solution i tried :
jq -c . $old |
while IFS= read -r obj; do
vpcidold=$( printf '%s' "$obj" | jq '.SecurityGroups[].VpcId')
securityidold=$( printf '%s' "$obj" | jq '.SecurityGroups[].GroupId')
echo "${vpcidold}||${securityidold}"
done > oldtest.json
it is working file but giving data in a line by line and want to do more optimised this with for loop.
How can I create a loop on JSON array to get desire output
"SG": [
{
"Description": "des",
"GroupName": "Gpname",
"IpPermissions": [
{
"FromPort": 80,
"IpProtocol": "tcp",
"IpRanges": [
{
"CidrIp": "0.0.0.0/0"
}
],
"Ipv6Ranges": [],
"PrefixListIds": [],
"ToPort": 80,
"UserIdGroupPairs": []
}
],
"OwnerId": "123",
"GroupId": "sg",
"IpPermissionsEgress": [
{
"IpProtocol": "-1",
"IpRanges": [
{
"CidrIp": "0.0.0.0/0"
}
],
"Ipv6Ranges": [],
"PrefixListIds": [],
"UserIdGroupPairs": []
}
],
"Tags": [
{
"Key": "projectcode",
"Value": "none"
},
{
"Key": "sgid",
"Value": "sg-123"
}
],
"VpcId": "vpc-123"
}
]
},

Answer 1

If the JSON file is just an array of the objects, you don't need to loop over them in bash. jq will loop over them implicitely:
jq -r '.[][][] | (.VpcId + "||" + .GroupId)' file.json
Tested on the following input:
[
{ "SG": [
{
"Description": "des",
"GroupName": "Gpname",
"GroupId": "sg",
"VpcId": "vpc-123"
}
] },
{ "SG": [
{
"Description": "des",
"GroupName": "xyz",
"GroupId": "sg-12345",
"VpcId": "vpc-12345"
}
] }
]
Output:
vpc-123||sg
vpc-12345||sg-12345