From 007e7d7b5e51ffb6b0f7a76cf24e232886252b5b Mon Sep 17 00:00:00 2001 From: Aadit Agrawal Date: Tue, 21 Jan 2025 15:38:19 +0530 Subject: [PATCH] Update OS/bash/Week4/SQLPlus.md --- OS/bash/Week4/SQLPlus.md | 60 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 59 insertions(+), 1 deletion(-) diff --git a/OS/bash/Week4/SQLPlus.md b/OS/bash/Week4/SQLPlus.md index 343ac06..fd1e73c 100644 --- a/OS/bash/Week4/SQLPlus.md +++ b/OS/bash/Week4/SQLPlus.md @@ -366,7 +366,7 @@ DRIVER_ID# REGNO REPORT_NUMBER DAMAGE_AMOUNT 1238 HFSP5601 5 1500 1238 HFSP5601 12 95500 ``` - +## Q3 Updating data entries: ```sql SQL> update participated set damage_amount=25000 where regno='HFSP5601' and report_number=12; @@ -387,6 +387,8 @@ DRIVER_ID# REGNO REPORT_NUMBER DAMAGE_AMOUNT 1238 HFSP5601 5 1500 1238 HFSP5601 12 25000 ``` + +## Q4 ### Dropping an attribute ```sql SQL> alter table Participated @@ -416,3 +418,59 @@ SQL> alter table Participated Table altered. ``` +### Conditional Deletion +```sql +SQL> select * from accident; + +REPORT_NUMBER ACCD_DATE LOCATION +------------- --------- -------------------------------------------------- + 1 01-JAN-24 Delhi India + 3 29-FEB-24 India + 4 11-OCT-93 Daman and Diu India + 5 31-MAR-00 Gujrat India + 12 17-JUL-00 karnataka India + +SQL > delete from accident where extract(year from accd_date)=1993; + +1 row deleted. + +SQL> select * from accident; + +REPORT_NUMBER ACCD_DATE LOCATION +------------- --------- -------------------------------------------------- + 1 01-JAN-24 Delhi India + 3 29-FEB-24 India + 5 31-MAR-00 Gujrat India + 12 17-JUL-00 karnataka India +``` + +## Q5 + +```sql +SQL> alter table Participated drop constraint fkey3participated; + +Table altered. + +SQL> alter table Participated add constraint fkey3participated foreign key(report_number) references accident(report_number) on delete cascade; + + +Table altered. +``` + +## Q6 + +```sql +SQL> alter table participated add constraint checkparticipated check(Damage_amount>=0); + +Table altered. + +SQL> select * from participated; + +DRIVER_ID# REGNO REPORT_NUMBER DAMAGE_AMOUNT +------------------------------ -------------------- ------------- ------------- +1234 ABCD0001 1 10000 +1236 DSDS0001 3 150 +1238 HFSP5601 5 1500 +1238 HFSP5601 12 25000 + +``` \ No newline at end of file