Python MySQL Update Table






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Python MySQL Update Table



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Update Table


You can update existing records in a table by using
the "UPDATE" statement:




Example


Overwrite the address column from "Valley 345" to "Canyoun 123":



import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
 
user="yourusername",
  passwd="yourpassword",
  database="mydatabase"
)

mycursor =
mydb.cursor()

sql = "UPDATE customers SET address = 'Canyon 123'
WHERE address = 'Valley 345'"

mycursor.execute(sql)

mydb.commit()

print(mycursor.rowcount, "record(s) affected")

Run example »



Important!: Notice the statement:
mydb.commit(). It is required to make the
changes, otherwise no
changes are made to the table.





Notice the WHERE clause in the UPDATE syntax: The WHERE clause
specifies which record or records that should be updated. If you omit the WHERE
clause, all records will be updated!







Prevent SQL Injection


It is considered a good practice to escape the values of any query, also in
update statements.


This is to prevent SQL injections, which is a common web hacking technique to
destroy or misuse your database.


The mysql.connector module uses the placeholder %s to escape values in the delete statement:



Example


Escape values by using the placholder %s
method:



import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
 
user="yourusername",
  passwd="yourpassword",
  database="mydatabase"
)

mycursor = mydb.cursor()

sql = "UPDATE customers SET address = %s
WHERE address = %s"
val = ("Valley 345", "Canyon 123")

mycursor.execute(sql,
val)

mydb.commit()

print(mycursor.rowcount, "record(s)
affected")

Run example »





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