How to properly query Postgres JSONB field in Vapor/Fluent - fluent

Question

I have a table with some jsonb columns created by a migration like this:
public func prepare(on database: Database) -> EventLoopFuture<Void> {
return database.schema(MyTable.schema)
.id()
.field(.metadata, .custom("JSONB"), .required)
.create()
}
I am trying to filter query on jsonb field. The following is a simple string interpolation that works.
//jsonFilters is a dictionary of key value pair for which we want to filter in jsonb field
var query = MyTable.query(on: db)
var filterString = ""
var cycleCount = 0;
jsonFilters.forEach({
(key, value) in
filterString +=
"metadata->>'\(key)' = '\(value)' "
cycleCount+=1
if(cycleCount < filter.metadata!.count) {
filterString += " AND "
}
})
query = query.filter(.custom(metadataString))
// Also filter on something else.
query = query.filter(....)
However this is not secure and is sql injection vulnerable. Is there a way to bind the filter arguments in for example using SQLQueryString? It should work in conjunction with the rest of the regular filter. ( Last line in the code)

Answer 1

Just in case someone runs into the same here is what works with SQLQueryString so you can pass the parameters instead of string interpolation:
var queryString = SQLQueryString("")
var cycleCount = 0;
filter.metadata!.forEach({
(key, value) in
queryString.appendLiteral("metadata->>")
queryString.appendInterpolation(bind: key)
queryString.appendLiteral(" = ")
queryString.appendInterpolation(bind: value)
cycleCount+=1
if(cycleCount < filter.metadata!.count) {
queryString.appendLiteral(" AND ")
}
})