SQL to MongoDB

妖狐艹你老母 2022-09-24 01:17 125阅读 0赞

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.

## Terminology and Concepts ##

The following table presents the various SQL terminology and concepts and the corresponding MongoDB terminology and concepts.

## 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.

### Insert ###

The following table presents the various SQL statements related to inserting records into tables and the corresponding MongoDB statements.

### Select ###

The following table presents the various SQL statements related to reading records from tables and the corresponding MongoDB statements.

<table style="margin:0px; padding:0px; border:1px solid silver; border-collapse:collapse; word-break:break-word"> 
 <thead style="margin:0px; padding:0px"> 
 <tr style="margin:0px; padding:0px"> 
 <th style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> SQL SELECT Statements</th> 
 <th style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> MongoDB find() Statements</th> 
 <th style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> Reference</th> 
 </tr> 
 </thead> 
 <tbody style="margin:0px; padding:0px"> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find()
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT id, user_id, status
FROM users
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 },
 {
 user_id: 1, status: 1 }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT user_id, status
FROM users
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 },
 {
 user_id: 1, status: 1, _id: 0 }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE status = "A"
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 status: "A" }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT user_id, status
FROM users
WHERE status = "A"
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 status: "A" },
 {
 user_id: 1, status: 1, _id: 0 }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE status != "A"
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 status: {
 $ne: "A" } }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="$ne" href="http://docs.mongodb.org/manual/reference/operators/#_S_ne" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$ne</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE status = "A"
AND age = 50
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 status: "A",
 age: 50 }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="$and" href="http://docs.mongodb.org/manual/reference/operators/#_S_and" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$and</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE status = "A"
OR age = 50
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 $or: [ {
 status: "A" } ,
 {
 age: 50 } ] }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="$or" href="http://docs.mongodb.org/manual/reference/operators/#_S_or" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$or</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE age &gt; 25
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 age: {
 $gt: 25 } }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="$gt" href="http://docs.mongodb.org/manual/reference/operators/#_S_gt" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$gt</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE age &lt; 25
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 age: {
 $lt: 25 } }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="$lt" href="http://docs.mongodb.org/manual/reference/operators/#_S_lt" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$lt</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE age &gt; 25
AND age &lt;= 50
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 age: {
 $gt: 25, $lte: 50 } }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>,&nbsp;<a title="$gt" href="http://docs.mongodb.org/manual/reference/operators/#_S_gt" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$gt</a>, and&nbsp;<a title="$lte" href="http://docs.mongodb.org/manual/reference/operators/#_S_lte" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$lte</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE user_id like "%bc%"
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 user_id: /bc/ }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="$regex" href="http://docs.mongodb.org/manual/reference/operators/#_S_regex" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$regex</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE user_id like "bc%"
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find(
 {
 user_id: /^bc/ }
)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="$regex" href="http://docs.mongodb.org/manual/reference/operators/#_S_regex" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$regex</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE status = "A"
ORDER BY user_id ASC
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find( {
 status: "A" } ).sort( {
 user_id: 1 } )
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="cursor.sort" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.sort" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">sort()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
WHERE status = "A"
ORDER BY user_id DESC
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find( {
 status: "A" } ).sort( {
 user_id: -1 } )
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="cursor.sort" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.sort" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">sort()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT COUNT(*)
FROM users
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.count()
</pre> 
 </div> 
 </div> or 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find().count()
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="cursor.count" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.count" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">count()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT COUNT(user_id)
FROM users
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.count( {
 user_id: {
 $exists: true } } )
</pre> 
 </div> 
 </div> or 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find( {
 user_id: {
 $exists: true } } ).count()
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>,&nbsp;<a title="cursor.count" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.count" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">count()</a>, and&nbsp;<a title="$exists" href="http://docs.mongodb.org/manual/reference/operators/#_S_exists" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$exists</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT COUNT(*)
FROM users
WHERE age &gt; 30
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.count( {
 age: {
 $gt: 30 } } )
</pre> 
 </div> 
 </div> or 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find( {
 age: {
 $gt: 30 } } ).count()
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>,&nbsp;<a title="cursor.count" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.count" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">count()</a>, and&nbsp;<a title="$gt" href="http://docs.mongodb.org/manual/reference/operators/#_S_gt" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">$gt</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT DISTINCT(status)
FROM users
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.distinct( "status" )
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="db.collection.distinct" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.distinct" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">distinct()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
LIMIT 1
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.findOne()
</pre> 
 </div> 
 </div> or 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find().limit(1)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>,&nbsp;<a title="db.collection.findOne" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.findOne" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">findOne()</a>, and&nbsp;<a title="cursor.limit" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.limit" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">limit()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">SELECT *
FROM users
LIMIT 5
SKIP 10
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find().limit(5).skip(10)
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>,&nbsp;<a title="cursor.limit" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.limit" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">limit()</a>, and&nbsp;<a title="cursor.skip" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.skip" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">skip()</a>&nbsp;for more information.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px"> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">EXPLAIN SELECT *
FROM users
WHERE status = "A"
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> 
 <div style="margin:0px; padding:0px"> 
 <div style="margin:0px; padding:0px"> 
 <pre style="margin-top:0px; margin-bottom:0px; padding:0px; white-space:pre-wrap; word-wrap:break-word">db.users.find( {
 status: "A" } ).explain()
</pre> 
 </div> 
 </div> </td> 
 <td style="margin:0px; padding:3px; border:1px solid silver; border-collapse:collapse"> See&nbsp;<a title="db.collection.find" href="http://docs.mongodb.org/manual/reference/javascript/#db.collection.find" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">find()</a>&nbsp;and&nbsp;<a title="cursor.explain" href="http://docs.mongodb.org/manual/reference/javascript/#cursor.explain" style="margin:0px; padding:0px; color:rgb(7,93,179)" rel="nofollow">explain()</a>&nbsp;for more information.</td> 
 </tr> 
 </tbody> 
</table>

### Update Records ###

The following table presents the various SQL statements related to updating existing records in tables and the corresponding MongoDB statements.

### Delete Records ###

The following table presents the various SQL statements related to deleting records from tables and the corresponding MongoDB statements.

[Frequently Asked Questions]: http://docs.mongodb.org/manual/faq/