Java Operation mongodb--Querying data

Querying the document information in a collection through the Find method

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Find ()

Query all document information, return finditerable<document>

We can get the document information through the Finditerable foreach method

Mongoclient mongoclient = new Mongoclient ();

Mongodatabase db = mongoclient.getdatabase ("test");
mongocollection<document> doc = db.getcollection ("text");

Finditerable<document> iter = Doc.find ();
Iter.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

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Conditional query

Document<field<value)

field is a query, value is a query, or a filter filters,filters provides a static method for a series of query conditions

Equal-=

Finditerable<document> iter = Doc.find (new Document ("name", "Zhang San"));

or finditerable<document> iter = Doc.find ("Age", New document ("$eq", 24));

or finditerable<document> iter = Doc.find (Filters.eq ("name", "Zhang San"));

Iter.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

Unequal-!=

Finditerable<document> iter = Doc.find ("Age", New document ("$ne", 24));
Finditerable<document> iter = Doc.find (filters.ne ("name", "Zhang San"));
Iter.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

Greater than

Finditerable<document> iter = Doc.find ("Age", New document ("$GT", 22));

or finditerable<document> iter = Doc.find (filters.gt ("age", 22));

Iter.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

Greater than or equal to->=

Use the same as above, the symbol is $GTE

Less than-<

finditerable<document> iter1 = doc.find (New document ("Age", New document ("$lt", 22)));

or finditerable<document> iter = Doc.find (filters.lt ("age", 22));
Iter1.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

Less than or equal to-<=

Use the same as above, the symbol is $lte

and-and

finditerable<document> iter1 = Doc.find (New Document ("Age"), append ("name", "Zhang San"));
or finditerable<document> Iter1 = Doc.find (Filters.and (Filters.eq ("name", "Zhang San"), filters.lt ("age", 30));
Iter1.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

or-or.

list<document> list = new arraylist<document> ();
List.add (New Document ("name", "Zhang San"));
List.add (New Document ("Age", 24));
finditerable<document> iter1 = Doc.find (New Document ("$or", list));
finditerable<document> iter1 = Doc.find (Filters.and (Filters.eq ("name", "Zhang San"), filters.lt ("age", 30));
Iter1.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

Presence-in

list<string> list = new arraylist<string> ();
List.add ("Zhang San");
List.add ("John Doe");
Finditerable<document> iter = doc.find (New document ("name", New Document ("$in", list));
Finditerable<document> iter = Doc.find (filters.in ("name", "Zhang San", "John Doe", "Harry"));
Iter.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

Does not exist-not in

Use the same as above, the symbol is $nin

Sort-sort

finditerable<document> iter1 = Doc.find (). Sort (New Document ("Age", 1). Append ("Phone", 1));

finditerable<document> iter1 = Doc.find (). Sort (Sorts.orderby (sorts.ascending ("Age"), Sorts.descending (" (phone ")));
Iter1.foreach (New block<document> () {
public void Apply (Document _doc) {
System.out.println (_doc.tojson ());
}
});

Java Operation mongodb--Querying data