# Editor example Join tables - working with multiple SQL tables

Data in relational databases is often stored over multiple tables, partitioned by the data type and then joined together using SQL JOIN queries. Editor, like DataTables, can use nested Javascript objects, making working with multiple tables super easy. Additionally the server-side libraries provide a left join method to make working with joins on the server-side just as easy as on the client-side - see the Editor server-side manual for further information (PHP | .NET | NodeJS).

This example shows a simple and common use-case for joined data - a foreign reference key, pointing to another record. In this case the users database table has a column called site which is a reference to the sites database table. Using the left join method method in Editor server-side libraries, the returned data structure for each row looks like:

    {
    	"DT_RowId": "row_1",
    	"users": {
    		"first_name": "Quynn",
    		"last_name": "Contreras",
    		"phone": "1-971-977-4681",
    		"site": "1"
    	},
    	"sites": {
    		"name": "Edinburgh"
    	}
    }

To display these fields in DataTables we use the `columns.data` option to access the nested data - for example `users.first_name` (using dotted Javascript object notation).

On create, edit and remove, Editor will also update the database accordingly for these actions automatically. With Editor, editing joined tables takes seconds to configure saving you a huge amount of time.

Finally, note that the Location select list is populated with a list of options retrieved from the server. This is done automatically by Editor when it detects a list of `options` (input / output options) for a field in the response for a data load event in a table (PHP: `Field->options()` | .NET: `Field.Options()` | NodeJS: `Field.options()`). The list of options can also be populated using the `select` field type's `update()` method.

As an alternative to the `select` used in this example for the Site input selector, Editor also has a built in `datatable` field type which will show the list of options as a DataTable with all the advantages that brings.

First name | Last name | Phone # | Location
--- | --- | --- | ---
First name | Last name | Phone # | Location

- JavaScript
- HTML
- CSS
- Ajax
- Server-side script

The JavaScript shown below is used to initialise the table shown in this example:

`const editor = new DataTable.Editor({ ajax: '../php/join.php', fields: [ { label: 'First name:', name: 'users.first_name' }, { label: 'Last name:', name: 'users.last_name' }, { label: 'Phone #:', name: 'users.phone' }, { label: 'Site:', name: 'users.site', type: 'select', placeholder: 'Select a location' } ], table: '#example' }); new DataTable('#example', { ajax: { url: '../php/join.php', type: 'POST' }, columns: [ { data: 'users.first_name' }, { data: 'users.last_name' }, { data: 'users.phone' }, { data: 'sites.name' } ], layout: { topStart: { buttons: [ { extend: 'create', editor: editor }, { extend: 'edit', editor: editor }, { extend: 'remove', editor: editor } ] } }, select: true });`

In addition to the above code, the following JavaScript library files are loaded for use in this example:

The HTML shown below is the raw HTML table element, before it has been enhanced by DataTables:

This example uses a little bit of additional CSS beyond what is loaded from the library files (below), in order to correctly display the table. The additional CSS used is shown below:

``

The following CSS library files are loaded for use in this example to provide the styling of the table:

This table loads data by Ajax. The latest data that has been loaded is shown below. This data will update automatically as any additional data is loaded.

The script used to perform the server-side processing for this table is shown below. Please note that this is just an example script using PHP. Server-side processing scripts can be written in any language, using the protocol described in the DataTables documentation.