首页 > 代码库 > Mongodb 与 SQL 语句对照表
Mongodb 与 SQL 语句对照表
In addition to the charts that follow, you might want to consider the Frequently Asked Questions section for a selection of common questions about MongoDB.
Executables
The following table presents the MySQL/Oracle executables and the corresponding MongoDB executables.
| MySQL/Oracle | MongoDB | |
|---|---|---|
| Database Server | mysqld/oracle | mongod |
| Database Client | mysql/sqlplus | mongo |
Terminology and Concepts
The following table presents the various SQL terminology and concepts and the corresponding MongoDB terminology and concepts.
| SQL Terms/Concepts | MongoDB Terms/Concepts |
|---|---|
| database | database |
| table | collection |
| row | document or BSON document |
| column | field |
| index | index |
| table joins | embedded documents and linking |
primary key Specify any unique column or column combination as primary key. | primary key In MongoDB, the primary key is automatically set to the _id field. |
| aggregation (e.g. group by) | aggregation framework See the SQL to Aggregation Framework Mapping Chart. |
Examples
The following table presents the various SQL statements and the corresponding MongoDB statements. The examples in the table assume the following conditions:
The SQL examples assume a table named users.
The MongoDB examples assume a collection named users that contain documents of the following prototype:
{ _id: ObjectID("509a8fb2f3f4948bd2f983a0"), user_id: "abc123", age: 55, status: ‘A‘}
Create and Alter
The following table presents the various SQL statements related to table-level actions and the corresponding MongoDB statements.
| SQL Schema Statements | MongoDB Schema Statements | Reference |
|---|---|---|
CREATE TABLE users ( id MEDIUMINT NOT NULL AUTO_INCREMENT, user_id Varchar(30), age Number, status char(1), PRIMARY KEY (id)) | Implicitly created on first insert operation. The primary key _id is automatically added if _id field is not specified. db.users.insert( { user_id: "abc123", age: 55, status: "A" } )However, you can also explicitly create a collection: db.createCollection("users") | See insert() and createCollection() for more information. |
ALTER TABLE usersADD join_date DATETIME | Collections do not describe or enforce the structure of the constituent documents. See the Schema Design wiki page for more information. | See update() and $set for more information on changing the structure of documents in a collection. |
ALTER TABLE usersDROP COLUMN join_date | Collections do not describe or enforce the structure of the constituent documents. See the Schema Design wiki page for more information. | See update() and $set for more information on changing the structure of documents in a collection. |
CREATE INDEX idx_user_id_ascON users(user_id) | db.users.ensureIndex( { user_id: 1 } ) | See ensureIndex() and indexes for more information. |
CREATE INDEX idx_user_id_asc_age_descON users(user_id, age DESC) | db.users.ensureIndex( { user_id: 1, age: -1 } ) | See ensureIndex() and indexes for more information. |
DROP TABLE users | db.users.drop() | See drop() for more information. |
Insert
The following table presents the various SQL statements related to inserting records into tables and the corresponding MongoDB statements.
| SQL INSERT Statements | MongoDB insert() Statements | Reference |
|---|---|---|
INSERT INTO users(user_id, age, status)VALUES ("bcd001", 45, "A") | db.users.insert( { user_id: "bcd001", age: 45, status: "A"} ) | See insert() for more information. |
Select
The following table presents the various SQL statements related to reading records from tables and the corresponding MongoDB statements.
| SQL SELECT Statements | MongoDB find() Statements | Reference |
|---|---|---|
SELECT *FROM users | db.users.find() | See find() for more information. |
SELECT id, user_id, statusFROM users | db.users.find( { }, { user_id: 1, status: 1 }) | See find() for more information. |
SELECT user_id, statusFROM users | db.users.find( { }, { user_id: 1, status: 1, _id: 0 }) | See find() for more information. |
SELECT *FROM usersWHERE status = "A" | db.users.find( { status: "A" }) | See find() for more information. |
SELECT user_id, statusFROM usersWHERE status = "A" | db.users.find( { status: "A" }, { user_id: 1, status: 1, _id: 0 }) | See find() for more information. |
SELECT *FROM usersWHERE status != "A" | db.users.find( { status: { $ne: "A" } }) | See find() and $ne for more information. |
SELECT *FROM usersWHERE status = "A"AND age = 50 | db.users.find( { status: "A", age: 50 }) | See find() and $and for more information. |
SELECT *FROM usersWHERE status = "A"OR age = 50 | db.users.find( { $or: [ { status: "A" } , { age: 50 } ] }) | See find() and $or for more information. |
SELECT *FROM usersWHERE age > 25 | db.users.find( { age: { $gt: 25 } }) | See find() and $gt for more information. |
SELECT *FROM usersWHERE age < 25 | db.users.find( { age: { $lt: 25 } }) | See find() and $lt for more information. |
SELECT *FROM usersWHERE age > 25AND age <= 50 | db.users.find( { age: { $gt: 25, $lte: 50 } }) | See find(), $gt, and $lte for more information. |
SELECT *FROM usersWHERE user_id like "%bc%" | db.users.find( { user_id: /bc/ }) | See find() and $regex for more information. |
SELECT *FROM usersWHERE user_id like "bc%" | db.users.find( { user_id: /^bc/ }) | See find() and $regex for more information. |
SELECT *FROM usersWHERE status = "A"ORDER BY user_id ASC | db.users.find( { status: "A" } ).sort( { user_id: 1 } ) | See find() and sort() for more information. |
SELECT *FROM usersWHERE status = "A"ORDER BY user_id DESC | db.users.find( { status: "A" } ).sort( { user_id: -1 } ) | See find() and sort() for more information. |
SELECT COUNT(*)FROM users | db.users.count()or db.users.find().count() | See find() and count() for more information. |
SELECT COUNT(user_id)FROM users | db.users.count( { user_id: { $exists: true } } )or db.users.find( { user_id: { $exists: true } } ).count() | See find(), count(), and $exists for more information. |
SELECT COUNT(*)FROM usersWHERE age > 30 | db.users.count( { age: { $gt: 30 } } )or db.users.find( { age: { $gt: 30 } } ).count() | See find(), count(), and $gt for more information. |
SELECT DISTINCT(status)FROM users | db.users.distinct( "status" ) | See find() and distinct() for more information. |
SELECT *FROM usersLIMIT 1 | db.users.findOne()or db.users.find().limit(1) | See find(), findOne(), and limit() for more information. |
SELECT *FROM usersLIMIT 5SKIP 10 | db.users.find().limit(5).skip(10) | See find(), limit(), and skip() for more information. |
EXPLAIN SELECT *FROM usersWHERE status = "A" | db.users.find( { status: "A" } ).explain() | See find() and explain() for more information. |
Update Records
The following table presents the various SQL statements related to updating existing records in tables and the corresponding MongoDB statements.
| SQL Update Statements | MongoDB update() Statements | Reference |
|---|---|---|
UPDATE usersSET status = "C"WHERE age > 25 | db.users.update( { age: { $gt: 25 } }, { $set: { status: "C" } }, { multi: true }) | See update(), $gt, and $set for more information. |
UPDATE usersSET age = age + 3WHERE status = "A" | db.users.update( { status: "A" } , { $inc: { age: 3 } }, { multi: true }) | See update(), $inc, and $set for more information. |
Delete Records
The following table presents the various SQL statements related to deleting records from tables and the corresponding MongoDB statements.
| SQL Delete Statements | MongoDB remove() Statements | Reference |
|---|---|---|
DELETE FROM usersWHERE status = "D" | db.users.remove( { status: "D" } ) | See remove() for more information. |
DELETE FROM users | db.users.remove( ) | See remove() for more information. |
Mongodb 与 SQL 语句对照表