لطفا منتظر باشید ...
UPDATE
UPDATE [LOW_PRIORITY] [IGNORE] tbl_name
SET col_name=expr, ...
[WHERE where_definition]
[ORDER BY ...]
[LIMIT #]
The UPDATE query updates existing table entries by
assigning new values to the specified columns. Columns that are not listed
are left alone, with the exception of the TIMESTAMP column
(see "TIMESTAMP[(M )]
MySQL column types TIMESTAMP
Description: A timestamp (date/time),
in YYYYMMDD..."). The WHERE clause lets
you specify a condition (where_definiton)
that rows must satisfy if they are to be updated, while the LIMIT clause
lets you specify a maximum number of rows to be updated.
| Important | If WHERE and LIMIT are not specified, then every row in the table will be updated! |
The ORDER BY clause lets you specify the order in
which entries are updated. This is most useful in combination with the LIMIT clause—together
they let you create queries like “update the 10 most recent rows”.An UPDATE operation will fail with an error if the
new value assigned to a row clashes with an existing value in a PRIMARY
KEY or UNIQUE column, unless the IGNORE option
is specified, in which case the query will simply have no effect on that particular
row.The LOW_PRIORITY option instructs MySQL to wait until
there are no other clients reading the table before it performs the update.
