Updating Records via SQL Query in Python
Now let's learn how to change records. This is done using the UPDATE
command. It has the following syntax:
query = "UPDATE table SET field = value WHERE condition"
with connection.cursor(dictionary=True) as cursor:
cursor.execute(query)
connection.commit()
With the UPDATE
command, you must use the commit
method:
with connection.cursor(dictionary=True) as cursor:
cursor.execute(query)
connection.commit()
Be careful, if you do not specify a block with WHERE
in the query, then during the update all the original records will be replaced by new ones.
Example
Let's change the user's age and salary:
query = "UPDATE users SET age=20, salary=800 WHERE id=1"
Example
Let's set the salary to 400
and the age to 24
for all users aged 23
:
query = "UPDATE users SET age=24, salary=300 WHERE age=23"
Practical tasks
Using the dump of the users
table you created earlier, restore it to its original state.
For a user with id
4
, set the age to 35
years.
For everyone whose salary is 500
, make it 700
.
For workers with id
greater than 2
and less than 5
inclusive, set the age to 23
.