docs: thoroughly document DataTypes

.eslintrc.cjs

@@ -18,6 +18,9 @@ module.exports = {
     'prefer-object-has-own': 'off',
     'unicorn/prefer-at': 'off',
     'unicorn/prefer-string-replace-all': 'off',
+
+    'unicorn/prefer-spread': 'off',
+    'unicorn/no-useless-undefined': 'off',
   },
   overrides: [{
     files: ['*.mdx/**', '*.md/**'],

docs/core-concepts/model-basics.md

@@ -308,18 +308,22 @@ sequelize.define('User', {
 });
 ```
 
-Some special values, such as `DataTypes.NOW`, are also accepted:
+It is possible to use `fn` to use a native SQL function as the default value:
 
 ```js
 sequelize.define('Foo', {
-  bar: {
-    type: DataTypes.DATETIME,
-    defaultValue: DataTypes.NOW
-    // This way, the current date/time will be used to populate this column (at the moment of insertion)
+  myUuid: {
+    type: DataTypes.UUID,
+    defaultValue: fn('uuid_generate_v4'),
   }
 });
 ```
 
+Sequelize provides a series of built-in default values you can use:
+
+- [`DataTypes.NOW`](../other-topics/other-data-types.mdx#built-in-default-values-for-dates)
+- [`DataTypes.UUIDV1`, `DataTypes.UUIDV4`](../other-topics/other-data-types.mdx#built-in-default-values-for-uuid)
+
 ## Data Types
 
 Every column you define in your model must have a data type. Sequelize provides [a lot of built-in data types](https://github.com/sequelize/sequelize/blob/main/src/data-types.js). To access a built-in data type, you must import `DataTypes`:
@@ -402,7 +406,7 @@ For UUIDs, use `DataTypes.UUID`. It becomes the `UUID` data type for PostgreSQL
 
 ### Others
 
-There are other data types, covered in a [separate guide](../other-topics/other-data-types.md).
+There are other data types, covered in a [separate guide](../other-topics/other-data-types.mdx).
 
 ## Column Options
 

docs/core-concepts/model-querying-basics.md

@@ -428,11 +428,78 @@ WHERE (
 )
 ```
 
+### Querying JSON
+
+JSON can be queried in three different ways:
+
+```js
+// Nested object
+await Foo.findOne({
+  where: {
+    meta: {
+      video: {
+        url: {
+          [Op.ne]: null
+        }
+      }
+    }
+  }
+});
+
+// Nested key
+await Foo.findOne({
+  where: {
+    "meta.audio.length": {
+      [Op.gt]: 20
+    }
+  }
+});
+
+// Containment
+await Foo.findOne({
+  where: {
+    meta: {
+      [Op.contains]: {
+        site: {
+          url: 'http://google.com'
+        }
+      }
+    }
+  }
+});
+```
+
+#### MSSQL
+
+MSSQL does not have a JSON data type, however it does provide some support for JSON stored as strings through certain functions since SQL Server 2016. Using these functions, you will be able to query the JSON stored in the string, but any returned values will need to be parsed seperately.
+
+```js
+// ISJSON - to test if a string contains valid JSON
+await User.findAll({
+  where: sequelize.where(sequelize.fn('ISJSON', sequelize.col('userDetails')), 1)
+});
+
+// JSON_VALUE - extract a scalar value from a JSON string
+await User.findAll({
+  attributes: [[ sequelize.fn('JSON_VALUE', sequelize.col('userDetails'), '$.address.Line1'), 'address line 1']]
+});
+
+// JSON_VALUE - query a scalar value from a JSON string
+await User.findAll({
+  where: sequelize.where(sequelize.fn('JSON_VALUE', sequelize.col('userDetails'), '$.address.Line1'), '14, Foo Street')
+});
+
+// JSON_QUERY - extract an object or array
+await User.findAll({
+  attributes: [[ sequelize.fn('JSON_QUERY', sequelize.col('userDetails'), '$.address'), 'full address']]
+});
+```
+
 ### Postgres-only Range Operators
 
 Range types can be queried with all supported operators.
 
-Keep in mind, the provided range value can [define the bound inclusion/exclusion](../other-topics/other-data-types.md#ranges-postgresql-only) as well.
+Keep in mind, the provided range value can [define the bound inclusion/exclusion](../other-topics/other-data-types.mdx#ranges-postgresql-only) as well.
 
 ```js
 [Op.contains]: 2,            // @> '2'::integer  (PG range contains element operator)

docs/other-topics/extending-data-types.md

@@ -1,6 +1,6 @@
 # Extending Data Types
 
-Most likely the type you are trying to implement is already included in our built-in [DataTypes](./other-data-types.md). If a new datatype is not included, this manual will show how to write it yourself.
+Most likely the type you are trying to implement is already included in our built-in [DataTypes](./other-data-types.mdx). If a new datatype is not included, this manual will show how to write it yourself.
 
 Sequelize doesn't create new DataTypes in the database. This tutorial explains how to make Sequelize recognize new DataTypes and assumes that those new DataTypes are already created in the database.