Lesson 1

This module covers the techniques you can use to create, edit, and test SQL scripts within Oracle's SQL*Plus environment.
You have already seen the SQL*Plus environment in previous modules whenever you worked with a simulation. Here you get to try out the features built into SQL*Plus that warrant the "Plus" in its name.

Question: Is the SQL*Plus interface the best environment for testing SQL scripts within Oracle?
SQL*Plus is a widely used command-line tool for interacting with Oracle Database. It is extremely versatile and is embedded with various features, making it a viable choice for testing SQL scripts. However, whether it is the 'best' environment for testing SQL scripts depends on several factors, including user preference, the complexity of scripts, and the specific requirements of your tasks. SQLPlus provides a straightforward and direct way of interacting with Oracle databases. It allows users to execute SQL statements, PL/SQL code, and SQLPlus commands interactively, or to run them from script files. It also enables users to format, perform calculations on, store, and print query results.
However, SQL*Plus does have its limitations. It is a bare-bones interface with no graphical elements, which might be a disadvantage for users who prefer a more visual environment. The lack of a GUI can make more complex database operations tedious or even daunting for newer users. For complex scripting and debugging, Integrated Development Environments (IDEs) like Oracle SQL Developer, TOAD, or PL/SQL Developer may be more efficient. These tools come with features such as:

1. Syntax Highlighting: This makes it easier to read and understand code, reducing the chances of making errors.
2. Debugging Tools: These tools allow you to set breakpoints, step through code, and examine the current state of your program.
3. Auto-Completion: This feature saves you time by completing the names of tables, columns, and other database objects as you type.
4. Schema Browsers: These help you to understand the structure of your database, which can be particularly useful when you are writing complex SQL queries.
5. Performance Profiling: Profiling tools can help you to identify parts of your code that are running slowly and could potentially be optimized.

Therefore, while SQL*Plus is an effective tool for running and testing SQL scripts in Oracle, it may not be the best choice for all scenarios. Developers who need more robust tools for debugging, code editing, and database exploration may prefer a more feature-rich SQL IDE. The 'best' environment truly depends on the specific needs, skill level, and preference of the user.

By the end of this module, you will know how to:

1. Describe SQL*Plus and identify when to use it
2. Change text by using the SQL*Plus text editor and run a query
3. Change a query by using a text editor
4. Save a query to a file, replace a file, edit a file
5. Modify column headings and display width in a column
6. Define the environment settings for SQL*Plus reports
7. Describe what gets saved in a file when using SPOOL

SQL*Plus is an interactive and batch query tool that is installed with every Oracle Database installation. It has a command-line user interface, a Windows Graphical User Interface (GUI) and the iSQL*Plus web-based user interface. There is also the SQL*Plus Instant Client which is a stand-alone command-line interface available on platforms that support the OCI Instant Client. SQL*Plus Instant Client connects to any available Oracle database, but does not require its own Oracle database installation. See the Oracle Call Interface Programmer's Guide for more information on the OCI Instant Client. SQL*Plus has its own commands and environment, and it provides access to the Oracle Database. It enables you to enter and execute SQL, PL/SQL, SQL*Plus and operating system commands to perform the following:

1. Format, perform calculations on, store, and print from query results
2. Examine table and object definitions
3. Develop and run batch scripts
4. Perform database administration

You can use SQL*Plus to generate reports interactively, to generate reports as batch processes, and to output the results to text file, to screen, or to HTML file for browsing on the Internet. You can generate reports dynamically using the HTML output facility of SQL*Plus, or using the dynamic reporting capability of iSQL*Plus to run a script from a web page. The next lesson is an overview of the background and future development of the SQL*Plus programming environment.