How
to insert, update, and delete data
Exercises
To
test whether a table has been modified correctly as you do these
exercises, you can write and run an appropriate SELECT statement.
- Write
an INSERT statement that adds this row to the Categories table:
category_name:Brass
Code
the INSERT statement so MySQL automatically generates the category_id
column.
-
Write
an UPDATE statement that modifies the row you just added to the
Categories table. This statement should change the product_name
column to “Woodwinds”, and it should use the category_id column
to identify the row.
-
Write
a DELETE statement that deletes the row you added to the Categories
table in exercise 1. This statement should use the category_id
column to identify the row.
- Write
an INSERT statement that adds this row to the Products table:
Use
a column list for this statement.
-
Write
an UPDATE statement that modifies the product you added in exercise
4. This statement should change the discount_percent column from 0%
to 35%.
-
Write
a DELETE statement that deletes the record with category_id = 4 from
the Categories table. When you execute this statement, it will
produce an error since the category has related rows in the Products
table. To fix that, precede the DELETE statement with another DELETE
statement that deletes all products in this category. (Remember that
to code two or more statements in a script, you must end each
statement with a semicolon.)