Conditional Search a string & concat with another field using MongoDB aggregation - regex

Question

I would like to search a set of documents on a field called SERVICES.
When I search, and
IF : I find first word or words at the beginning of string is Mail or Envelopes delivered or Lost suitcase or Found mail.
THEN : I add to the string SERVICES a period and string value of LAGUAGES field. LAGUAGES string is: ‘Needs immediate action’.
Sample Data:
/* 1 */
{
"SERVICES" : "Mail has been packaged and sitting in mail room",
"LAGUAGES" : "Needs immediate action"
}
/* 2 */
{
"SERVICES" : "Envelopes delivered to client but were not signed for by anyone",
"LAGUAGES" : "Needs immediate action"
}
/* 3 */
{
"SERVICES" : "There were problems with the client's luggage",
"LAGUAGES" : "Needs immediate action"
}
/* 4 */
{
"SERVICES" : "Lost suitcase at airport while in transit",
"LAGUAGES" : "Needs immediate action"
}
/* 5 */
{
"SERVICES" : "Found mail sitting at airport mailing room",
"LAGUAGES" : "Needs immediate action"
}
Required Output:
/* 1 */
{
"SERVICES" : "Mail has been packaged and sitting in mail room. Needs immediate action"
}
/* 2 */
{
"SERVICES" : "Envelopes delivered to client but were not signed for by anyone. Needs immediate action"
}
/* 3 */
{
"SERVICES" : "Lost suitcase at airport while in transit. Needs immediate action"
}
/* 4 */
{
"SERVICES" : "Found mail sitting at airport mailing room. Needs immediate action"
}
Tried below query:
I did a $match first just to filter the information but seems to only filter the last $OR in my statement. Need help.
{
$match: {
$or: [
{
SERVICES: { $regex: "Mail.* " },
SERVICES: { $regex: "Envelopes delivered.* " },
SERVICES: { $regex: "Lost suitcase. * " },
SERVICES: { $regex: "Found mail. * " },
},
];
}
}
How do I search these strings and return the above output. Thanks.

Answer 1

You need to use aggregation's $concat operator :
db.collection.aggregate([
{
$match: {
$or: [
{
SERVICES: { $regex: /^Mail/ }
},
{
SERVICES: { $regex: /^Envelopes delivered/ }
},
{
SERVICES: { regex: /^Lost suitcase/ }
},
{
SERVICES: { $regex: /^Found mail/ }
}
]
}
},
/** `$addFields` will re-create `SERVICES` field with new concated string value
* Or if you just want `SERVICES` field then use `$project` with `_id :0 ` */
{$addFields : {SERVICES : {$concat : ['$SERVICES','.',' ','$LAGUAGES']}}}
])
Or you can use $in instead of $or :
db.collection.aggregate([
{ $match: { SERVICES: { $in: [/^Mail/, /^Envelopes delivered/, /^Lost suitcase/, /^Found mail/] } } } ,
{$addFields : {SERVICES : {$concat : ['$SERVICES', '.', ' ','$LAGUAGES']}}}
]);