mongodb array containing only one elemnt code example
Example 1: mongodb find array with element
// Finds all documents that have a property named "tags"
// which has at least one array element matching "red"
db.inventory.find( { tags: "red" } )
Example 2: find string element in an array mongodb
db.articles.find({
"stock.country" : "01",
"stock.warehouse.code" : "02"
}).pretty();