Add page on value (#694)

Co-authored-by: ekwuno <[email protected]>

doc-surrealdb_versioned_docs/version-latest/surrealql/datamodel/values.mdx

@@ -0,0 +1,93 @@
+---
+sidebar_position: 16
+sidebar_label: Values
+title: Values | SurrealQL
+description: Every type in SurrealDB is a value
+
+---
+
+# Values
+
+Each of the types mentioned in the data model is a subset of an all-encompassing type called a value.
+
+## Comparing and ordering values
+
+While it is unsurprising that a data type can be compared with itself, it may be surprising that different types can also be compared with each other.
+
+```surql
+RETURN 9 > 1;            // Returns true
+RETURN [] > time::now(); // Also returns true
+```
+
+This comparison is possible because every type in SurrealDB is a subset of value, and a comparison of any type with another is also simply a comparison of a value with another value. The order of values from least to greatest is:
+
+* `none`
+* `null`
+* `bool`
+* `number`
+* `string`
+* `duration`
+* `datetime`
+* `UUID`
+* `array`
+* `object`
+* `geometry`
+* `bytes`
+* `record`
+
+As a result, all of the following return `true`.
+
+```surql
+RETURN [
+    null > none,
+    true > null,
+    1 > true,
+    'a' > 999999999,
+    1s > 'a',
+    time::now() > 1s,
+    rand::uuid() > time::now(),
+    [] > rand::uuid(),
+    {} > [],
+    (89.0, 89.0) > {},
+    <bytes>'Aeon' > (89.0, 89.0),
+    person:aeon > <bytes>'Aeon'
+];
+```
+
+Being able to compare a value with any other value is what makes SurrealDB's record range syntax possible. As the least possible value is NONE, a query for the records below that begins with NONE and ends with the `..` open range syntax will return everything.
+
+```surql
+CREATE time_data:['2024-07-23T06:36:56.004Z'];
+CREATE time_data:['2024-07-24T06:36:56.014Z'];
+CREATE time_data:['2024-07-25T06:36:56.014Z'];
+SELECT * FROM time_data:[<datetime>'2024-07-24']..;
+SELECT * FROM time_data:[NONE]..;
+```
+
+Inside a schema, the keyword `any` is used to denote any possible value.
+
+```surql
+DEFINE FIELD anything ON TABLE person TYPE any;
+```
+
+## Values and truthiness
+
+Any value is considered to be truthy if it is not NONE, NULL, or a default value for the data type. A data type at its default value is one that is empty, such as an empty string or array or object, or a number set to 0.
+
+The following example shows the result of the `array::all()` method, which checks to see if all of the items inside an array are truthy or not.
+
+```surql
+RETURN array::all(["", 1, 2, 3]); // false because of ""
+RETURN array::all([{}, 1, 2, 3]); // false because of {}
+RETURN array::all(["SurrealDB", { is_nice_database: true }, 1, 2, 3]);  // true
+```
+
+As [the ! operator](../operators/#not) reverses the truthiness of a value, a doubling of this operator can also be used to check for truthiness.
+
+```surql
+RETURN [
+    !!"Has a value", !!"",             // true, false
+    !!true, !!false,                   // true, false
+    !!{ is_nice_database: true }, !!{} // true, false
+    ];
+```

doc-surrealdb_versioned_docs/version-latest/surrealql/operators.mdx

@@ -28,7 +28,11 @@ A variety of operators in SurrealQL allow for complex manipulation of data, and
     </tr>
     <tr>
         <td scope="row" data-label="Operator"><a href="#not"><code>!</code></a></td>
-        <td scope="row" data-label="Description">Reverses the truthiness of a boolean value</td>
+        <td scope="row" data-label="Description">Reverses the truthiness of a value</td>
+    </tr>
+    <tr>
+        <td scope="row" data-label="Operator"><a href="#not_not"><code>!!</code></a></td>
+        <td scope="row" data-label="Description">Determines the truthiness of a value</td>
     </tr>
     <tr>
       <td scope="row" data-label="Operator"><a href="#nco"><code>??</code></a></td>
@@ -203,16 +207,30 @@ SELECT * FROM 0 OR false OR 10;
 
 ## `!` {#not}
 
-Reverses the truthiness of a boolean value.
+Reverses the truthiness of a value.
 
 ```surql
 SELECT * FROM !(TRUE OR FALSE)
 
-FALSE
+false
+
+SELECT * FROM !"Has a value";
+
+false
 ```
 
 <br />
 
+## `!!` {#not_not}
+
+Determines the truthiness of a value (simply an application of the `!` operator twice).
+
+```surql
+SELECT * FROM !!"Has a value";
+
+true
+```
+
 ## `??` {#nco}
 
 Check whether either of two values are truthy and not `NULL`.