| SQL 查询语句 | MongoDB find() 语句 |
| SELECT *FROM users | db.users.find() |
| SELECT id, user_id, statusFROM users | db.users.find( { }, { user_id: 1, status: 1 }) |
| SELECT user_id, statusFROM users | db.users.find( { }, { user_id: 1, status: 1, _id: 0 }) |
| SELECT *FROM usersWHERE status = “A” | db.users.find( { status: “A” }) |
| SELECT user_id, statusFROM usersWHERE status = “A” | db.users.find( { status: “A” }, { user_id: 1, status: 1, _id: 0 }) |
| SELECT *FROM usersWHERE status != “A” | db.users.find( { status: { $ne: “A” } }) |
| SELECT *FROM usersWHERE status = “A”AND age = 50 | db.users.find( { status: “A”, age: 50 }) |
| SELECT *FROM usersWHERE status = “A”OR age = 50 | db.users.find( { $or: [ { status: “A” } , { age: 50 } ] }) |
| SELECT *FROM usersWHERE age > 25 | db.users.find( { age: { $gt: 25 } }) |
| SELECT *FROM usersWHERE age < 25 | db.users.find( { age: { $lt: 25 } }) |
| SELECT *FROM usersWHERE age > 25AND age <= 50 | db.users.find( { age: { $gt: 25, $lte: 50 } }) |
| SELECT *FROM usersWHERE user_id like “%bc%” | db.users.find( { user_id: /bc/ } ) |
| SELECT *FROM usersWHERE user_id like “bc%” | db.users.find( { user_id: /^bc/ } ) |
| SELECT *FROM usersWHERE status = “A”ORDER BY user_id ASC | db.users.find( { status: “A” } ).sort( { user_id: 1 } ) |
| SELECT *FROM usersWHERE status = “A”ORDER BY user_id DESC | db.users.find( { status: “A” } ).sort( { user_id: -1 } ) |
| SELECT COUNT(*)FROM users | db.users.count()or
db.users.find().count() |
| SELECT COUNT(user_id)FROM users | db.users.count( { user_id: { $exists: true } } )or
db.users.find( { user_id: { $exists: true } } ).count() |
| SELECT COUNT(*)FROM usersWHERE age > 30 | db.users.count( { age: { $gt: 30 } } )or
db.users.find( { age: { $gt: 30 } } ).count() |
| SELECT DISTINCT(status)FROM users | db.users.distinct( “status” ) |
| SELECT *FROM usersLIMIT 1 | db.users.findOne()or
db.users.find().limit(1) |
| SELECT *FROM usersLIMIT 5SKIP 10 | db.users.find().limit(5).skip(10) |
| EXPLAIN SELECT *FROM usersWHERE status = “A” | db.users.find( { status: “A” } ).explain() |