MongoDB Query Command detailed

1. Check all records

Copy the code code as follows:

Db.userInfo.find ();

Equivalent:select* from UserInfo;

The default is 20 records per page, and you can query the next page of data with the IT iteration command when the display is not displayed. Note: Type the it command cannot take ";"

But you can set the size of the data displayed on each page, using dbquery.shellbatchsize=; This results in 50 records per page.

2. Duplicate data for a column in the current clustered collection after the query is removed

Copy the code code as follows:

Db.userInfo.distinct ("name");

Will filter out the same data in name

equivalent: select Distict name from UserInfo;

3. Check the record of age = 22

Copy the code code as follows:

Db.userInfo.find ({"Age": 22});

Equivalent to: select * from userInfo where age =;

4. Check the records of age > 22

Copy the code code as follows:

Db.userInfo.find ({age: {$gt: 22}});

Equivalent to:select * from UserInfo where >22;

5. Check the records of age < 22

Copy the code code as follows:

Db.userInfo.find ({age: {$lt: 22}});

Equivalent to:select * from UserInfo where <22;

6. Check the records of age >= 25
Copy the code code as follows:

Db.userInfo.find ({age: {$gte: 25}});

Equivalent to:select * from UserInfo where age >=;

7. Check the records of age <= 25
Copy the code code as follows:

Db.userInfo.find ({age: {$lte: 25}});

8. Query age >= 23 and age <= 26

Copy the code code as follows:

Db.userInfo.find ({age: {$gte: $lte: 26}});

9. Query the data containing MONGO in name
Copy the code code as follows:

Db.userInfo.find ({name:/mongo/});

Equal to percent

SELECT * from UserInfo where name is like '%mongo% ';

10, query the name in the beginning of MONGO
Copy the code code as follows:

Db.userInfo.find ({name:/^mongo/});

SELECT * from UserInfo where name is like ' mongo% ';

11. Query the specified column name, age data

Copy the code code as follows:

Db.userInfo.find ({}, {name:1, age:1});

Equivalent: select name, age from UserInfo;
Of course name can also be used with true or false, as in the case of Ture River Name:1 effect, if False is to exclude name, display column information other than name.

12. Query the specified column name, age data, age > 25

Copy the code code as follows:

Db.userInfo.find ({age: {$gt: +}}, {name:1, age:1});

Equivalent: select name, age from UserInfo where >25;

13. Sort by age

Copy the code code as follows:

Ascending:

Db.userInfo.find (). Sort ({age:1});

Descending:

Db.userInfo.find (). Sort ({Age:-1});

14. Query name = Zhangsan, age = 22 data
Copy the code code as follows:

Db.userInfo.find ({name: ' Zhangsan ', age:22});

Equivalent: SELECT * from userInfo where name = ' Zhangsan ' and "age = '";

15, query the first 5 data

Copy the code code as follows:

Db.userInfo.find (). Limit (5);

Equivalent: Select Top 5 * from UserInfo;

16, query 10 after the data

Copy the code code as follows:

Db.userInfo.find (). Skip (10);

Equivalent:

SELECT * from UserInfo where ID not in (

Select Top Ten * from UserInfo
);

17, query the data between 5-10

Copy the code code as follows:

Db.userInfo.find (). Limit (Ten). Skip (5);

Limit is the number of limits displayed, and Skip is the number skipped.

18, OR and query

Copy the code code as follows:

Db.userInfo.find ({$or: [{age:22}, {age:25}]});

Equivalent: SELECT * from userInfo where age = n or age =;

19. Query the first piece of data

Copy the code code as follows:

Db.userInfo.findOne ();

Equivalent:

Select top 1 * from UserInfo;

Db.userInfo.find (). limit (1);

20. Query the number of record bars for a result set
Copy the code code as follows:

Db.userInfo.find ({age: {$gte: +}}). Count ();

Equivalent to:select COUNT (*) from userInfo where age >=;

21. Sort by a column
Copy the code code as follows:

Db.userInfo.find ({sex: {$exists: true}}). Count ();

equivalent to: select count (Sex) from UserInfo;

MongoDB Query Command detailed