The Connections navigator lists all our database connections created by us. A double-click on each of those database connections will open the database connection for us using the saved credentials for that particular database. Objects are grouped into nodes in the Connections navigator to reflect their types. They are ordered by most commonly used with Tables, Views, and Indexes at the top of the list. You can refer to the following screenshot to see the grouping, order, and some of the currently available types displayed in the Connections navigator. The selection of browsable object types available increases with each release as the SQL Developer team adds support for more features. SQL Developer allows you to explore the contents of your database using the connection tree.

A complete list of supported database object types can be seen in the following screenshot:

To work with any object, select and expand the respective object node. The most common node you'll work with is the Tables node. This displays all of the tables the user owns (all of the tables in the schema). Each of the object nodes is identified by an icon, and the Tables node highlights some of the main table types using these icons. Not all are singled out, but the more commonly used ones are. If you expand the HR Tables node, then the COUNTRIES table, which in the sample is an index-organized table, is identified by the slightly different table icon used. Partitioned tables are also distinguished from regular, simple tables using icons. The following screenshot displays the index organized, regular, external, partitioned, and temporary icons:

Once you have expanded an object type node in the Connections navigator, selecting any object in that node opens a window of tabs, called display editors, which define the object. Each editor displays a data grid of details describing the selected object. These are based on queries against the data dictionary and you can get the same results by writing the SQL yourself.

The number and types of editors displayed will vary depending on the object or database that you are connected to. If you are connected to Oracle Database 11g or above, then an additional Flashback editor displays with the other table display editors.

The contents of each display editor are displayed in data grids, which typically have three or more columns of data within the grid. A few are two column name-value pair data grids, such as the Details editor. The data in these grids is not editable and merely reflects the details about the object or structure selected. There are two exceptions. The first exception is the Data editor included with the set of display editors for certain objects, such as tables and views. The Data editor displays the instance data for a table and, depending on the object, this data can be edited and the changes can be committed to the database. The second exception is the Code editor for PL/SQL objects, where you are placed into a PL/SQL editor when you select the object.

Data grids throughout SQL Developer have context menus on the column's headings and the data grid itself. You can control the layout and what data is displayed by using these two context menus. For the remaining...

As you select each of the other database objects, you'll notice that the set of display editors varies considerably.

It would be tedious to single out each of the object nodes and describe them here. The display editors and data grids behave the same for each of them.

Working with PL/SQL objects

Triggers, functions, procedures, and packages all have their own separate nodes in the Connections navigator. A single-click on any object in these PL/SQL nodes opens as editable PL/SQL code, as shown here:

In the preceding screenshot, the initial Code editor is the editable PL/SQL code editor. This Code editor is included in the set of display editors for the selected procedure.

Tip

Unlike with other database objects, each new selected PL/SQL object opens a new window. In other words, the windows are automatically pinned for the PL/SQL windows. For more information, see the Chapter 4, Working with PL/SQL.

In the first section of the chapter, we looked at browsing objects and data in the database. You may, if you are an application developer and working with a completed database design, spend most of your time doing just that. It is more likely, though, that you'll need to make changes such as adding or modifying structures and data. SQL Developer provides the dialogs to assist you.

In the same way that you can write SQL queries to extract information about the objects you have access to, you can write the SQL Data Definition Language (DDL) to create, edit, and modify these objects. Almost all of the object nodes in the Connections navigator provide a context menu to create a new object. To invoke a dialog that creates any new object, select the object in the navigator and invoke the context menu.

The following list is an exception for creating new objects using context menus: