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If you run this query, it will insert data in the table, as shown in Figure 8.22.

FOR ONLINE READING ONLY

Figure 8.22: INSERT data in the table Chapter Eight: Databases and Database Management Systems

(b) UPDATE
The update command is used to update the data value in a table column. After inserting
data, you can modify it by using the update command. The syntax is: UPDATE
table_name SET column1 = ‘value1’, column2 = ‘value2’, WHERE condition;
WHERE is used to specify which data should be modified. If the condition is not
specified, ALL the rows in a table will be modified. For example, suppose you want
to update the student’s first name with studentID number 1234 from Mwakalinga to
Musawomda. In that case, you will apply the following query: UPDATE student_
registration SET FirstName =’Musawomda ‘WHERE studentId = 1234; Output is
as shown in Figure 8.18 (a) and (b).

Figure 8.23 (a): Update query

Figure 8.23 (b): Select query of the updated record
(c) DELETE
The DELETE command is used to delete existing records in a table. After inserting
data, you can delete the data by using the delete command. The syntax is DELETE
FROM table_name WHERE condition;

For example: if you want to delete all the information about Musawomda from our
previous example, the query will be: DELETE FROM student_registration WHERE
FirstName=’ Musawomda ‘; this query will delete all records with the first name
Musawomda. If you want to delete only the record for Musawomda with studentId
1234, you should write the following query:

DELETE FROM student_registration WHERE studentId=1234;

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Student’s Book Form Five

Computer Science Form 5.indd 471 23/07/2024 12:35