Search Algorithm Implementation using NodeJS + MongoDB(or SQL) - sql

Question

There is an application with search input that gives an opportunity to search for contacts by their information stored in database.
For example, I can type 0972133122 Alan and my search engine must return all contacts whose firstname is Alan & whose numbers match 0972133122 string.
Of course, I can just type Alan 0972, for instance, and there must be returned all possible contacts matching this pattern. The query order may be different, so that I can type 0972 Alan Smith, and if there are 2 contacts with Alan names and whose phone numbers start with 0972, then additional Smith clarification should return the only 1 contact.
I suggest built in phone applications for Android make use of this search algorithm:
So that my goal is to achieve similar result, but I do know how to do this. Here my code:
GraphQL query
query contacts {
contacts(input: {
contactQuery: "Alan Smith"
}) {
name {
firstName
lastName
}
}
}
NodeJS query to MongoDB
const conditions = {};
const expr = contactQuery
.split(' ')
.map((contact) => new RegExp(`${contact}`, 'i'))
conditions.$or = [
{ 'firstName': { $in: expr } },
{ 'lastName': { $in: expr } },
{ 'university': { $in: expr } },
{ emails: { $elemMatch: { email: { $in: expr } } } },
{ phones: { $elemMatch: { phone: { $in: expr } } } },
{ socials: { $elemMatch: { id: { $in: expr } } } },
]
const contacts = await this.contacts
.find(conditions, undefined)
.exec()
This works partly, but I receive unwanted documents from MongoDB:
{
contacts: [
{
firstName: "Alan",
lastName: "Smith",
university: "KNTU",
...
},
{
firstName: "Alan",
lastName: "Alderson", // should not be returned
university: "ZNU",
...
},
...
]
}
But I need to get one contact that has strictly Alan firstname and Smith lastname. If it's impossible to do with MongoDB, -- please, provide me an example of SQL query. Any suggestions & solutions will be accepted!
Please, let me know if my question still is not clear.

Answer 1

Firstly, you need to separate out the numbers and words from the search text and then you can create a possible combination of it for an example:
FirstName: Alan, LastName: Smith
FirstName: Smith, LastName: Alan
Using regex you can do this easily and then you can use logical operators of mongodb to create your query like this
Approach 1
db.collection.find({
$or: [
{
$and: [
{
firstName: {
$regex: "Alan",
$options: "i"
}
},
{
lastName: {
$regex: "Smith",
$options: "i"
}
}
]
},
{
$and: [
{
firstName: {
$regex: "Smith",
$options: "i"
}
},
{
lastName: {
$regex: "Alan",
$options: "i"
}
}
]
}
]
})
Here is the link to the playground for you to look at it in action Mongo Playground
Approach 2
Another way is where you concat all the searchable keys into one field and then use regex to filter it out like this
db.collection.aggregate([
{
$addFields: {
text: {
$concat: [
"$firstName",
" ",
"$lastName",
" ",
"$university",
" ",
"$phones"
]
}
}
},
{
$match: {
text: {
$regex: "(?=.*?(0972))(?=.*?(Alan))(?=.*?(Smith))",
$options: "i"
}
}
},
{
$project: {
text: 0
}
}
])
Code to build the query:
let text = "0972 Alan Smith";
let parts = text.split(" ");
let query = parts.map(part => "(?=.*?("+part+"))").join("");
console.log(query);
But you need to check the performance implication of this approach or you can create a view and then query to view to make your query more cleaner
Here is the link to the playground for you to look at it in action Mongo Playground