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DOCSP-32658-expand-replace-examples (#305)
* DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples * DOCSP-32658-expand-replace-examples --------- Co-authored-by: jason-price-mongodb <jshfjghsdfgjsdjh@aolsdjfhkjsdhfkjsdf.com>
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‎source/reference/ejson/stringify.txt

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@@ -49,6 +49,8 @@ The ``EJSON.stringify()`` method has these fields:
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- Modifies output. If the value exists but it is not an array or a
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function, ``EJSON.stringify()`` returns all document fields.
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``replacer`` can be an array or a function.
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.. list-table::
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:header-rows: 1
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:widths: 30 70
@@ -57,13 +59,19 @@ The ``EJSON.stringify()`` method has these fields:
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- Effect
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* - array
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- An array of document fields to include in the output
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- An array of document fields to include in the output. The
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array elements must specify the field names to include in
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the returned JSON string.
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* - function
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- A function that takes two parameters, ``key`` and
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``value``. ``key`` provides the function's ``this``
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context. EJSON returns the transformed ``value``. See
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below for an :ref:`example <ex-ejson-function>`
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context. EJSON returns the transformed ``value``.
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The function is run for each object. The object
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values are replaced with the function's return value.
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For an example, see :ref:`ex-ejson-function`.
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* - ``spacer``
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- integer or string
@@ -209,7 +217,7 @@ Use a Function to Transform Output Fields
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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To transform field values, use a JavaScript function to set the
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``replace`` option.
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``replacer`` option. For example:
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.. code-block:: javascript
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@@ -229,7 +237,10 @@ To transform field values, use a JavaScript function to set the
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The function runs recursively against the input object.
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Example output:
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.. code-block:: javascript
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:copyable: false
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[
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{
@@ -273,6 +284,156 @@ The function also modifies the ``quantity`` field in the output string.
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All of the ``quantity`` values are multiplied by two in the output
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string. ``EJSON.stringify()`` does not update the collection.
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Use a Function to Transform Output Fields in Nested Objects
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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Create the ``salesWithAddress`` collection with nested addresses:
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.. code-block:: javascript
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db.salesWithAddress.insertMany( [
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{ custId: 345, purchaseDate: ISODate("2023-07-04"),
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quantity: 4, cost: Decimal128("100.60"),
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address: { number: 100, street: "Main Street", ZIP: 12345 } },
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{ custId: 346, purchaseDate: ISODate("2023-07-12"),
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quantity: 3, cost: Decimal128("175.45"),
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address: { number: 200, street: "East Street", ZIP: 12345 } }
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] )
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The following example uses a ``replacer`` function to change the ZIP
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codes for the addresses to ``55555``:
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.. code-block:: javascript
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// Retrieve the salesWithAddress contents as an array and save
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// in queryResults
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let queryResults = db.salesWithAddress.find().toArray()
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// Define a replacer function to change the ZIP codes
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let replacer = function( key, value ) {
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if (key === 'address') {
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value.ZIP = 55555;
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}
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return value;
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}
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// Run EJSON.stringify() to change the ZIP codes in queryResults
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EJSON.stringify( queryResults, replacer, 3 )
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Example output:
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.. code-block:: javascript
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:copyable: false
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[
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{
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"_id": {
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"$oid": "65498c6562f443aa1490070f"
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},
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"custId": 345,
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"purchaseDate": {
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"$date": "2023-07-04T00:00:00Z"
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},
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"quantity": 4,
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"cost": {
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"$numberDecimal": "100.60"
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},
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"address": {
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"number": 100,
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"street": "Main Street",
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"ZIP": 55555
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}
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},
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{
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"_id": {
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"$oid": "65498c6562f443aa14900710"
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},
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"custId": 346,
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"purchaseDate": {
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"$date": "2023-07-12T00:00:00Z"
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},
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"quantity": 3,
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"cost": {
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"$numberDecimal": "175.45"
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},
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"address": {
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"number": 200,
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"street": "East Street",
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"ZIP": 55555
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}
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}
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]
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Use a Function to Replace BSON Strings
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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For a list of BSON data types and the corresponding numeric codes, see
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:manual:`BSON Types </reference/bson-types>`.
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The following example uses a ``replacer`` function to replace the BSON
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strings with the string ``"This is a string"``:
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.. code-block:: javascript
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// Retrieve the salesWithAddress contents as an array and save
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// in queryResults
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let queryResults = db.salesWithAddress.find().toArray()
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// Define a replacer function to replace the strings
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let replacer = function( key, value ) {
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if (typeof value === "string") {
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return "This is a string";
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}
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return value;
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}
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// Run EJSON.stringify() to replace the strings in queryResults
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EJSON.stringify( queryResults, replacer, 3 )
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Example output:
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.. code-block:: javascript
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:copyable: false
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[
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{
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"_id": {
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"$oid": "This is a string"
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},
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"custId": 345,
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"purchaseDate": {
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"$date": "This is a string"
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},
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"quantity": 4,
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"cost": {
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"$numberDecimal": "This is a string"
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},
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"address": {
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"number": 100,
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"street": "This is a string",
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"ZIP": 12345
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}
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},
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{
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"_id": {
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"$oid": "This is a string"
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},
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"custId": 346,
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"purchaseDate": {
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"$date": "This is a string"
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},
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"quantity": 3,
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"cost": {
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"$numberDecimal": "This is a string"
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},
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"address": {
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"number": 200,
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"street": "This is a string",
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"ZIP": 12345
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}
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}
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]
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Write to a File from Inside mongosh
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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