$or: If you aware with SQL Server, $or operator behave same like OR in SQL Server. $or operator uses to perform logical OR operation on two or more than two arrays and its select the documents that satisfy at least one of the expression.
Syntax:
{ $or: [ { <expression1> }, { <expression2> }, ... , { <expressionN> } ] } |
Example: Suppose we have a collection “Order” and want to select those records which quantity is 1or price is 200. See following collection.
{ "_id" : 1, "item" : "item1", "qty" : 1, "Price" : 500 } { "_id" : 2, "item" : "item1", "qty" : 2, "Price" : 200 } { "_id" : 3, "item" : "item1", "qty" : 4, "Price" : 300 } { "_id" : 4, "item" : "item1", "qty" : 8, "Price" : 700 } { "_id" : 5, "item" : "item1", "qty" : 2, "Price" : 500 } |
Run the following query to get exact result described above.
db.Order.find({$or:[{qty:1},{Price:200}]}) |
Result:
{ "_id" : 1, "item" : "item1", "qty" : 1, "Price" : 500 } { "_id" : 2, "item" : "item1", "qty" : 2, "Price" : 200 } |