A practical approach towards learning SQL in Oracle 11g. Video lectures are prepared as well and can be found at given link https://www.youtube.com/channel/UCMv6HrS_4_GFWmLLFzL_U_A?view_as=subscriber

1. SQL Fundamentals Oracle 11g
M U H A M M A D WA H E E D
O R AC L E DATA BA S E D E V E LO P E R
E M A I L : m .wa h e e d 3 6 6 8 @ g m a i l . co m
Lecture#9
Readable Outputs with
iSQL*Plus

2. Substitution Variables
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3. Substitution Variables(cont’d)
Use iSQL*Plus substitution variables to:
• Store values temporarily
- Single ampersand( & )
- Double ampersand( && )
- DEFINE command
•Pass variable values between SQL statements
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4. Substitution Variables(cont’d)
Use of & substitution variable:
• Use a variable with pre-fixed ampersand to prompt the user for a value
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5. Substitution Variables(cont’d)
Use of character and date substitution variables:
• Use single quotes with character and date values
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6. Substitution Variables(cont’d)
Use substitution variables to supplement the following :
•Entire SELECT statements
•Table names
•Column expressions
•WHERE conditions
•ORDER BY clauses
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7. Substitution Variables(cont’d)
Use substitution variables to supplement the following :
•Example:
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8. Substitution Variables(cont’d)
Use of DEFINE substitution variable:
• Creates a user variable with the CHAR data type
DEFINE variable = value (if value includes spaces than use single quotes to enclose the value)
• A defined variable is available for the session
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9. Substitution Variables(cont’d)
Use of DEFINE and UNDEFINE commands:
• A variable remains defined until you either
- Use the UNDEFINE command to clear it
- Exit iSQL*Plus
•You can verify changes with DEFINE command
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10. Substitution Variables(cont’d)
Use of && with substitution variables:
• If you want to reuse a variable value without prompting the user each time
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11. MERGE Statement
•It performs UPDATE if record exists and INSERT if record not found.
•Mostly used in data warehousing applications.
•Syntax:
MERGE INTO <receiver_table_name> <receiver_table_alias>
USING <sender_table_name> <table_alias>
ON (<receiver_table_alias>.<column_name>= <sender_table_alias>.<column_name>)
WHEN MATCHED THEN
UPDATE SET
<receiver_table_alias>.<column_name> = <sender_table_name>.<column_name>
WHEN NOT MATCHED THEN
INSERT VALUES(<sender_table_name>.<column_name> ,…..);
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12. MERGE Statement
•Syntax can be simply described as:
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13. Motivational Speaking
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14. Feedback/Suggestions?
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