The SQL UPDATE Statement
The UPDATE statement is used to update or modify one or more records in a table.
UPDATE Syntax
UPDATE table_name SET column1 = value1 , column2 = value2 , ... WHERE condition ;
Note
Be careful when updating records in a table! Notice the WHERE clause in the UPDATE statement. The WHERE clause specifies which record(s) that should be updated. If you omit the WHERE clause, all records in the table will be updated!
Demo Database
Below is a selection from the Customers table used in the examples:
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 | Alfreds Futterkiste | Maria Anders | Obere Str. 57 | Berlin | 12209 | Germany |
| 2 | Ana Trujillo Emparedados y helados | Ana Trujillo | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno TaquerÃa | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico |
| 4 | Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK |
| 5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |
UPDATE Table
The following SQL updates the record with CustomerID = 1, with a new contact person AND a new city.
Example
UPDATE Customers
SET ContactName = 'Alfred Schmidt', City= 'Frankfurt'
WHERE CustomerID = 1;The selection from the "Customers" table will now look like this:
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 | Alfreds Futterkiste | Alfred Schmidt | Obere Str. 57 | Frankfurt | 12209 | Germany |
| 2 | Ana Trujillo Emparedados y helados | Ana Trujillo | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno TaquerÃa | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico |
| 4 | Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK |
| 5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |
UPDATE Multiple Records
The WHERE clause determines which records that will be updated.
The following SQL will update the ContactName to "Juan" for ALL records where country is "Mexico":
Example
UPDATE Customers
SET ContactName='Juan'
WHERE Country='Mexico';The selection from the "Customers" table will now look like this:
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 | Alfreds Futterkiste | Alfred Schmidt | Obere Str. 57 | Frankfurt | 12209 | Germany |
| 2 | Ana Trujillo Emparedados y helados | Juan | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno TaquerÃa | Juan | Mataderos 2312 | México D.F. | 05023 | Mexico |
| 4 | Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK |
| 5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |
Update Warning!
Be careful when updating records. If you omit the WHERE clause, ALL records will be updated!
The following SQL will update the ContactName to "Juan" for ALL records:
Example
UPDATE Customers
SET ContactName='Juan';The selection from the "Customers" table will now look like this:
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 | Alfreds Futterkiste | Juan | Obere Str. 57 | Frankfurt | 12209 | Germany |
| 2 | Ana Trujillo Emparedados y helados | Juan | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno TaquerÃa | Juan | Mataderos 2312 | México D.F. | 05023 | Mexico |
| 4 | Around the Horn | Juan | 120 Hanover Sq. | London | WA1 1DP | UK |
| 5 | Berglunds snabbköp | Juan | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |