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To return all documents in a collection, use thefind() method without specifying search conditions. For example, the following operation returns all documents in thecountryinfo collection.

mysql-js> db.countryinfo.find()[     {          "GNP": 828,          "Code:": "ABW",          "Name": "Aruba",          "IndepYear": null,          "geography": {              "Continent": "North America",              "Region": "Caribbean",              "SurfaceArea": 193          },          "government": {              "GovernmentForm": "Nonmetropolitan Territory of The Netherlands",              "HeadOfState": "Beatrix"          }          "demographics": {              "LifeExpectancy": 78.4000015258789,              "Population": 103000          },          ...      } ]240 documents in set (0.00 sec)

The method produces results that contain operational information in addition to all documents in the collection.

An empty set (no matching documents) returns the following information:

Empty set (0.00 sec)

You can include search conditions with thefind() method. The syntax for expressions that form a search condition is the same as that of traditional MySQLChapter 14,Functions and Operators. You must enclose all expressions in quotes. For the sake of brevity, some of the examples do not display output.

A simple search condition could consist of theName field and a value we know is in a document. The following example returns a single document:

mysql-js> db.countryinfo.find("Name = 'Australia'")[    {        "GNP": 351182,        "Code:": "AUS",        "Name": "Australia",        "IndepYear": 1901,        "geography": {            "Continent": "Oceania",            "Region": "Australia and New Zealand",            "SurfaceArea": 7741220        },        "government": {            "GovernmentForm": "Constitutional Monarchy, Federation",            "HeadOfState": "Elisabeth II"        }        "demographics": {            "LifeExpectancy": 79.80000305175781,            "Population": 18886000        },    }]

The following example searches for all countries that have a GNP higher than $500 billion. Thecountryinfo collection measures GNP in units of million.

mysql-js> db.countryinfo.find("GNP > 500000")...[output removed]10 documents in set (0.00 sec)

The Population field in the following query is embedded within the demographics object. To access the embedded field, use a period between demographics and Population to identify the relationship. Document and field names are case-sensitive.

mysql-js> db.countryinfo.find("GNP > 500000 and demographics.Population < 100000000")...[output removed]6 documents in set (0.00 sec)

Arithmetic operators in the following expression are used to query for countries with a GNP per capita higher than $30000. Search conditions can include arithmetic operators and most MySQL functions.

mysql-js> db.countryinfo.find("GNP*1000000/demographics.Population > 30000")...[output removed]9 documents in set, 7 warnings (0.00 sec)Warning (Code 1365): Division by 0Warning (Code 1365): Division by 0Warning (Code 1365): Division by 0Warning (Code 1365): Division by 0Warning (Code 1365): Division by 0Warning (Code 1365): Division by 0Warning (Code 1365): Division by 0

You can separate a value from the search condition by using thebind() method. For example, instead of specifying a hard-coded country name as the condition, substitute a named placeholder consisting of a colon followed by a name that begins with a letter, such ascountry. Then use thebind(placeholder,value) method as follows:

mysql-js> db.countryinfo.find("Name = :country").bind("country", "Italy"){    "GNP": 1161755,    "_id": "00005de917d8000000000000006a",    "Code": "ITA",    "Name": "Italy",    "Airports": [],    "IndepYear": 1861,    "geography": {        "Region": "Southern Europe",        "Continent": "Europe",        "SurfaceArea": 301316    },    "government": {        "HeadOfState": "Carlo Azeglio Ciampi",        "GovernmentForm": "Republic"    },    "demographics": {        "Population": 57680000,        "LifeExpectancy": 79    }}1 document in set (0.01 sec)

You can use placeholders and thebind() method to create saved searches which you can then call with different values. For example to create a saved search for a country:

mysql-js> var myFind = db.countryinfo.find("Name = :country")mysql-js> myFind.bind('country', 'France'){    "GNP": 1424285,    "_id": "00005de917d80000000000000048",    "Code": "FRA",    "Name": "France",    "IndepYear": 843,    "geography": {        "Region": "Western Europe",        "Continent": "Europe",        "SurfaceArea": 551500    },    "government": {        "HeadOfState": "Jacques Chirac",        "GovernmentForm": "Republic"    },    "demographics": {        "Population": 59225700,        "LifeExpectancy": 78.80000305175781    }}1 document in set (0.0028 sec)mysql-js> myFind.bind('country', 'Germany'){    "GNP": 2133367,    "_id": "00005de917d80000000000000038",    "Code": "DEU",    "Name": "Germany",    "IndepYear": 1955,    "geography": {        "Region": "Western Europe",        "Continent": "Europe",        "SurfaceArea": 357022    },    "government": {        "HeadOfState": "Johannes Rau",        "GovernmentForm": "Federal Republic"    },    "demographics": {        "Population": 82164700,        "LifeExpectancy": 77.4000015258789    }}1 document in set (0.0026 sec)

You can return specific fields of a document, instead of returning all the fields. The following example returns the GNP and Name fields of all documents in thecountryinfo collection matching the search conditions.

Use thefields() method to pass the list of fields to return.

mysql-js> db.countryinfo.find("GNP > 5000000").fields(["GNP", "Name"])[    {        "GNP": 8510700,        "Name": "United States"    }]1 document in set (0.00 sec)

In addition, you can alter the returned documents—adding, renaming, nesting and even computing new field values—with an expression that describes the document to return. For example, alter the names of the fields with the following expression to return only two documents.

mysql-js> db.countryinfo.find().fields(mysqlx.expr('{"Name": upper(Name), "GNPPerCapita": GNP*1000000/demographics.Population}')).limit(2){    "Name": "ARUBA",    "GNPPerCapita": 8038.834951456311}{    "Name": "AFGHANISTAN",    "GNPPerCapita": 263.0281690140845}

You can apply thelimit(),sort(), andskip() methods to manage the number and order of documents returned by thefind() method.

To specify the number of documents included in a result set, append thelimit() method with a value to thefind() method. The following query returns the first five documents in thecountryinfo collection.

mysql-js> db.countryinfo.find().limit(5)... [output removed]5 documents in set (0.00 sec)

To specify an order for the results, append thesort() method to thefind() method. Pass to thesort() method a list of one or more fields to sort by and, optionally, the descending (desc) or ascending (asc) attribute as appropriate. Ascending order is the default order type.

For example, the following query sorts all documents by the IndepYear field and then returns the first eight documents in descending order.

mysql-js> db.countryinfo.find().sort(["IndepYear desc"]).limit(8)... [output removed]8 documents in set (0.00 sec)

By default, thelimit() method starts from the first document in the collection. You can use theskip() method to change the starting document. For example, to ignore the first document and return the next eight documents matching the condition, pass to theskip() method a value of 1.

mysql-js> db.countryinfo.find().sort(["IndepYear desc"]).limit(8).skip(1)... [output removed]8 documents in set (0.00 sec)