SQL Update statement With Example

SQL UPDATE Statement

• The UPDATE statement updates data values in a database.
• UPDATE can update one or more records in a table.
• Use the WHERE clause to UPDATE only specific records.

The SQL UPDATE syntax

The general syntax is:

1. UPDATE table-name SET column-name = value, column-name = value, ...

To limit the number of records to UPDATE append a WHERE clause:

1. UPDATE table-name SET column-name = value, column-name = value, ... WHERE condition

SQL UPDATE Examples

1) Normal update or without where condition update

mysql> update person set age=25;

Query OK, 4 rows affected (0.02 sec)

Rows matched: 5 Changed: 4 Warnings: 0

mysql> update person set sex='M';

Query OK, 1 row affected (0.02 sec)

Rows matched: 5 Changed: 1 Warnings: 0

mysql> select *from person;

+-----+--------+------+----------------------+------+------------+

| sno | name | age | email | sex | phone |

+-----+--------+------+----------------------+------+------------+

| 1 | subham | 25 | NULL | M | NULL |

| 2 | nunu | 25 | NULL | M | NULL |

| 3 | chayan | 25 | NULL | M | NULL |

| 4 | debo | 25 | NULL | M | NULL |

+-----+--------+------+----------------------+------+------------+

2) update with where condition

mysql> update person set sex='F' where sno='4';

Query OK, 1 row affected (0.01 sec)

Rows matched: 1 Changed: 1 Warnings: 0

mysql> select *from person;

+-----+--------+------+----------------------+------+------------+

| sno | name | age | email | sex | phone |

+-----+--------+------+----------------------+------+------------+

| 1 | subham | 25 | NULL | M | NULL |

| 2 | nunu | 25 | NULL | M | NULL |

| 3 | chayan | 25 | NULL | M | NULL |

| 4 | debo | 25 | NULL | F | NULL |

+-----+--------+------+----------------------+------+------------+

5 rows in set (0.00 sec)