- Oracle SQL*Plus: The Definitive Guide
- Preface
- 1. Introduction to SQL*Plus
- 2. Interacting with SQL*Plus
- 3. Generating Reports with SQL*Plus
- Following a Methodology
- Saving Your Work
- Designing a Simple Report
- Advanced Report Formatting
- Totals and Subtotals
- Other Reporting Topics
- 4. Writing SQL*Plus Scripts
- Why Write Scripts?
- Using Substitution Variables
- Prompting for Values
- Cleaning Up the Display
- Packaging Your Script
- The DEFINE and UNDEFINE Commands
- Controlling Variable Substitution
- Commenting Your Scripts
- 5. Extracting and Loading Data
- 6. Exploring Your Database
- 7. Advanced Scripting
- 8. Tuning and Timing
- 9. The Product User Profile
- 10. Administration with SQL*Plus
- 11. Customizing Your SQL*Plus Environment
- SQL*Plus Settings You Can Control
- The Site and User Profiles
- Environment Variable Settings
- The SET Command
- The SHOW Command
- A. SQL*Plus Command Reference
- SQLPLUS
- Comment Delimiters (/*...*/)
- Double Hyphen (- -)
- At Sign (@)
- Double At Sign (@@)
- Forward Slash (/)
- ACCEPT
- APPEND
- ARCHIVE LOG
- ATTRIBUTE
- BREAK
- BTITLE
- CHANGE
- CLEAR
- COPY
- COLUMN
- COMPUTE
- CONNECT
- DEFINE
- DEL
- DESCRIBE
- DISCONNECT
- EDIT
- EXECUTE
- EXIT
- GET
- HELP
- HOST
- INPUT
- LIST
- PASSWORD
- PAUSE
- PROMPT
- QUIT
- RECOVER
- REMARK
- REPFOOTER
- REPHEADER
- RUN
- SAVE
- SET
- SHOW
- SHUTDOWN
- SPOOL
- START
- STARTUP
- STORE
- TIMING
- TTITLE
- UNDEFINE
- VARIABLE
- WHENEVER
- B. SQL*Plus Format Elements
- Index
- Colophon
UNDEFINE is the opposite of DEFINE, and erases a user variable definition. UNDEFINE is discussed in Chapter 4 .
UNDEF[INE]variable_name[variable_name...]
where:
- UNDEF[INE]
Is the command, which may be abbreviated to UNDEF.
- variable_name
Is the name of a user variable to delete. You can delete several variables with one command by listing them out separated by spaces.
-
No Comment
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.