MongoDB Limit and Skip methods

MongoDB Limit () method

If you need to read a specified number of data records in MongoDB, you can use the MongoDB limit method, and the limit () method accepts a numeric parameter that specifies the number of record bars read from MongoDB. Grammar

The basic syntax for the limit () method is as follows:

>db. Collection_name.find (). Limit (number)

Example

The data in the collection col is as follows:

{"_id": ObjectId ("56066542ade2f21f36b0313a"), "title": "PHP Tutorial", "description": "PHP is a powerful server-side scripting language for creating dynamic interactive sites. "By": "Rookie Tutorial", "url": "Http://www.runoob.com", "tags": ["PHP"], "likes": $
{"_id": ObjectId ("56066549ade 2f21f36b0313b ")," title ":" Java Tutorial "," description ":" Java is a high-level programming language introduced by Sun Microsystems Company in May 1995. "By": "Rookie Tutorial", "url": "Http://www.runoob.com", "tags": ["Java"], "likes": [] {"
_id": ObjectId ("5606654fad e2f21f36b0313c ")," title ":" MongoDB Tutorial "," description ":" MongoDB is a Nosql database "," by ":" Rookie Tutorial "," url ":" Http://www.runo Ob.com "," tags ": [" MongoDB "]," likes ": 100}

The above example shows the two records in the query document:

> db.col.find ({},{"title": 1,_id:0}). Limit (2)
{"title": "PHP Tutorial"}
{"title": "Java Tutorial"}
>

Note: If you do not specify a parameter in the limit () method, all data in the collection is displayed. MongoDB Skip () method

In addition to using the limit () method to read a specified amount of data, we can also use the Skip () method to skip a specified number of data, and the Skip method also accepts a numeric parameter as the number of skipped records. Grammar

The Skip () method script syntax is formatted as follows:

>db. Collection_name.find (). Limit (number). Skip (number)

Example

The above example will only display the second document data

>db.col.find ({},{"title": 1,_id:0}). Limit (1). Skip (1)
{"title": "Java Tutorial"}
>

Note: The default parameter of the Skip () method is 0.