您的位置：首页 > 数据库 > Mongodb

SQL to MongoDB

2016-07-22 10:16 357 查看
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/OracleMongoDB
Database Servermysqld/oraclemongod
Database Clientmysql/sqlplusmongo

Terminology and Concepts

The following table presents the various SQL terminology and concepts and the corresponding MongoDB terminology and concepts.
SQL Terms/ConceptsMongoDB Terms/Concepts
databasedatabase
tablecollection
rowdocument or BSON document
columnfield
indexindex
table joinsembedded 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 _idfield.
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 StatementsMongoDB Schema StatementsReference
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 users
ADD 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 users
DROP 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_asc
ON users(user_id)


db.users.ensureIndex( { user_id: 1 } )


See ensureIndex() and indexes for
more information.
CREATE INDEX
idx_user_id_asc_age_desc
ON 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 StatementsMongoDB insert() StatementsReference
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 StatementsMongoDB find() StatementsReference
SELECT *
FROM users


db.users.find()


See find() for
more information.
SELECT id, user_id, status
FROM users


db.users.find(
{ },
{ user_id: 1, status: 1 }
)


See find() for
more information.
SELECT user_id, status
FROM 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, status
FROM 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 > 25
AND   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 5
SKIP 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 StatementsMongoDB update() StatementsReference
UPDATE users
SET 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 users
SET age = age + 3
WHERE 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 StatementsMongoDB remove() StatementsReference
DELETE FROM users
WHERE status = "D"


db.users.remove( { status: "D" } )


See remove() for
more information.
DELETE FROM users


db.users.remove( )


See remove() for
more information.
内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理 点击这里给我发消息
标签： 
相关文章推荐
新的分享
章节导航