diff --git a/OS/bash/Week4/SQLPlus.md b/OS/bash/Week4/SQLPlus.md
index 34e2651..3743ec7 100644
--- a/OS/bash/Week4/SQLPlus.md
+++ b/OS/bash/Week4/SQLPlus.md
@@ -72,6 +72,13 @@ SQL> desc PARTICIPATED
  REGNO                                     NOT NULL VARCHAR2(20)
  REPORT_NUMBER                             NOT NULL NUMBER(38)
  DAMAGE_AMOUNT                                      NUMBER(38)
+```
+
+Now, we enter values.
+```sql
+SQL> insert into person values(1234,'Rohan','Delhi India');
+
+1 row created.
 
 SQL> select * from person;
 
@@ -143,4 +150,188 @@ NAME
 ADDRESS
 --------------------------------------------------------------------------------
 Manipal India
-```
\ No newline at end of file
+```
+
+Now, we modify the varchar sizes so that we can fix the display formatting.
+
+```sql
+SQL> alter table person modify address varchar (30);
+
+Table altered.
+
+SQL> select * from person;
+
+DRIVER_ID#                     NAME
+------------------------------ ----------------------------------------
+ADDRESS
+------------------------------
+1234                           Rohan
+Delhi India
+
+1235                           Rohit
+Banglalore India
+
+1236                           Ramesh
+Baharashtra India
+
+
+DRIVER_ID#                     NAME
+------------------------------ ----------------------------------------
+ADDRESS
+------------------------------
+1237                           Saarthak
+Manipal India
+
+SQL> alter table person modify driver_id# varchar (4);
+
+Table altered.
+
+SQL> alter table person modify name varchar (10);
+
+Table altered.
+
+SQL> select * from person;
+
+DRIV NAME       ADDRESS
+---- ---------- ------------------------------
+1234 Rohan      Delhi India
+1235 Rohit      Banglalore India
+1236 Ramesh     Baharashtra India
+1237 Saarthak   Manipal India
+
+```
+
+Data updation.
+```sql
+SQL> update person set address='Maharashtra India' WHERE driver_id# = 1236;
+
+1 row updated.
+
+SQL> select * from person;
+
+DRIV NAME       ADDRESS
+---- ---------- ------------------------------
+1234 Rohan      Delhi India
+1235 Rohit      Banglalore India
+1236 Ramesh     Maharashtra India
+1237 Saarthak   Manipal India
+
+SQL> insert into person values(1238, 'Amogh', 'Muzaffarnagar');
+
+1 row created.
+```
+### Listing Tables
+```sql
+SQL> select table_name from user_tables;
+
+TABLE_NAME
+--------------------------------------------------------------------------------
+ACCIDENT
+CAR
+OWNS
+PARTICIPATED
+PERSON
+```
+More Data Entry.
+```sql
+SQL> insert into car values('ABCD0001','Celtos',3);
+
+1 row created.
+
+SQL> insert into car values('EFGH2001','Ferrari',32);
+
+1 row created.
+
+SQL> insert into car values('DSDS0001','Urus',5);
+
+1 row created.
+
+SQL> insert into car values('ABCD4001','Honda City',1);
+
+1 row created.
+
+SQL> insert into car values('HFSP5601','mini cooper',7);
+
+1 row created.
+
+SQL> select * from car;
+
+REGNO                MODEL                                YEAR
+-------------------- ------------------------------ ----------
+ABCD0001             Celtos                                  3
+EFGH2001             Ferrari                                32
+DSDS0001             Urus                                    5
+ABCD4001             Honda City                              1
+HFSP5601             mini cooper                             7
+
+SQL> insert into accident values(0001,'01-Jan-2024','Delhi India');
+
+1 row created.
+
+SQL> select * from accident;
+
+REPORT_NUMBER ACCD_DATE LOCATION
+------------- --------- --------------------------------------------------
+            1 01-JAN-24 Delhi India
+
+SQL> insert into accident values(0003,'29-feb-2024',' India');
+
+1 row created.
+
+SQL> insert into accident values(0004,'11-Oct-1993',' Daman and Diu India');
+
+1 row created.
+
+SQL> insert into accident values(0005,'31-march-2200',' Gujrat India');
+
+1 row created.
+
+SQL> insert into accident values(12,'17-july-2900',' karnataka India');
+
+1 row created.
+
+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> insert into owns values(1234,'ABCD0001');
+
+1 row created.
+
+SQL> insert into owns values(1235,'EFGH2001');
+
+1 row created.
+
+SQL> insert into owns values(1236,'DSDS0001');
+
+1 row created.
+
+SQL> insert into owns values(1237,'ABCD4001');
+
+1 row created.
+
+SQL> insert into owns values(1238,'HFSP5601');
+
+1 row created.
+
+SQL> select * from owns;
+
+DRIVER_ID#                     REGNO
+------------------------------ --------------------
+1234                           ABCD0001
+1235                           EFGH2001
+1236                           DSDS0001
+1237                           ABCD4001
+1238                           HFSP5601
+```
+Note: 
+```sql
+SQL> @<FILEPATH>/filename.sql
+``` 
+will import the commands from a doc and run them.
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