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Expressions régulières,
Syntaxe et mise en oeuvre :
GNU/Linux |
CentOS 2.1AS(Slurm) |
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update(l) |
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UPDATE − Replaces values of columns in a table
UPDATE [ ONLY ]
table SET col = expression [, ...]
[ FROM fromlist ]
[ WHERE condition ]
INPUTS
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table |
The name of an existing table. |
|||
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column |
The name of a column in table. |
expression
A valid expression or value to assign to column.
fromlist
A Postgres non-standard extension to allow columns from other tables to appear in the WHERE condition.
condition
Refer to the SELECT statement for a further description of the WHERE clause.
OUTPUTS
UPDATE #
Message returned if successful. The # means the number of rows updated. If # is 0 no rows are updated.
UPDATE changes the values of the columns specified for all rows which satisfy condition. Only the columns to be modified need appear as columns in the statement.
Array references use the same syntax found in SELECT [select(l)]. That is, either single array elements, a range of array elements or the entire array may be replaced with a single query.
You must have write access to the table in order to modify it, as well as read access to any table whose values are mentioned in the WHERE condition.
By default UPDATE will update tuples in the table specified and all its sub-tables. If you wish to only update the specific table mentioned, you should use the ONLY clause.
Change word "Drama" with "Dramatic" on column kind:
UPDATE films
SET kind = ’Dramatic’
WHERE kind = ’Drama’;
SELECT *
FROM films
WHERE kind = ’Dramatic’ OR kind =
’Drama’;
code | title |
did | date_prod | kind | len
-------+---------------+-----+------------+----------+-------
BL101 | The Third Man | 101 | 1949-12-23 | Dramatic | 01:44
P_302 | Becket | 103 | 1964-02-03 | Dramatic | 02:28
M_401 | War and Peace | 104 | 1967-02-12 | Dramatic | 05:57
T_601 | Yojimbo | 106 | 1961-06-16 | Dramatic | 01:50
DA101 | Das Boot | 110 | 1981-11-11 | Dramatic | 02:29
SQL92
SQL92 defines a different syntax for the positioned UPDATE
statement:
UPDATE
table SET column = expression [, ...]
WHERE CURRENT OF cursor
where cursor identifies an open cursor.
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update(l) | |