|Oracle® Database SQL Reference
10g Release 2 (10.2)
|PDF · Mobi · ePub|
For you to update values in a table, the table must be in your own schema or you must have the
UPDATE object privilege on the table.
For you to update values in the base table of a view:
You must have the
UPDATE object privilege on the view, and
Whoever owns the schema containing the view must have the
UPDATE object privilege on the base table.
TABLE system privilege also allows you to update values in any table or in the base table of any view.
You must also have the
SELECT object privilege on the object you want to update if:
The object is on a remote database or
SQL92_SECURITY initialization parameter is set to
TRUE and the
UPDATE operation references table columns, such as the columns in a
Specify a comment that passes instructions to the optimizer on choosing an execution plan for the statement.
You can place a parallel hint immediately after the
UPDATE keyword to parallelize both the underlying scan and
ONLY clause applies only to views. Specify
ONLY syntax if the view in the
UPDATE clause is a view that belongs to a hierarchy and you do not want to update rows from any of its subviews.
Specify the schema containing the object to be updated. If you omit
schema, then the database assumes the object is in your own schema.
Specify the name of the table, view, materialized view, or the columns returned by a subquery to be updated. Issuing an
UPDATE statement against a table fires any
UPDATE triggers associated with the table.
If you specify
view, then the database updates the base table of the view. You cannot update a view except with
OF triggers if the defining query of the view contains one of the following constructs:
WITH READ ONLY
You cannot update more than one base table through a view.
In addition, if the view was created with the
OPTION, then you can update the view only if the resulting data satisfies the view's defining query.
table or the base table of
view contains one or more domain index columns, then this statement executes the appropriate indextype update routine.
You cannot update rows in a read-only materialized view. If you update rows in a writable materialized view, then the database updates the rows from the underlying container table. However, the updates are overwritten at the next refresh operation. If you update rows in an updatable materialized view that is part of a materialized view group, then the database also updates the corresponding rows in the master table.
Specify the name of the partition or subpartition within
table targeted for updates. You need not specify the partition name when updating values in a partitioned table. However in some cases specifying the partition name can be more efficient than a complicated
Specify a complete or partial name of a database link to a remote database where the object is located. You can use a database link to update a remote object only if you are using Oracle Database distributed functionality.
If you omit
dblink, then the database assumes the object is on the local database.
See Also:"Referring to Objects in Remote Databases" for information on referring to database links
subquery_restriction_clause to restrict the subquery in one of the following ways:
WITH CHECK OPTION Specify
WITH CHECK OPTION to indicate that Oracle Database prohibits any changes to the table or view that would produce rows that are not included in the subquery. When used in the subquery of a DML statement, you can specify this clause in a subquery in the
FROM clause but not in subquery in the
CONSTRAINT constraint Specify the name of the
CHECK OPTION constraint. If you omit this identifier, then Oracle automatically assigns the constraint a name of the form
n, where n is an integer that makes the constraint name unique within the database.
table_collection_expression lets you inform Oracle that the value of
collection_expression should be treated as a table for purposes of query and DML operations. The
collection_expression can be a subquery, a column, a function, or a collection constructor. Regardless of its form, it must return a collection value—that is, a value whose type is nested table or varray. This process of extracting the elements of a collection is called collection unnesting.
The optional plus (+) is relevant if you are joining the
TABLE expression with the parent table. The + creates an outer join of the two, so that the query returns rows from the outer table even if the collection expression is null.
Note:In earlier releases of Oracle, when
collection_expressionwas a subquery,
table_collection_expressionwas expressed as
subquery. That usage is now deprecated.
You can use a
table_collection_expression to update rows in one table based on rows from another table. For example, you could roll up four quarterly sales tables into a yearly sales table.
Specify a correlation name (alias) for the table, view, or subquery to be referenced elsewhere in the statement. This alias is required if the
DML_table_expression_clause references any object type attributes or object type methods.
See Also:"Correlated Update: Example"
You cannot execute this statement if
table or the base table of
view contains any domain indexes marked
You cannot insert into a partition if any affected index partitions are marked
You cannot specify the
order_by_clause in the subquery of the
If you specify an index, index partition, or index subpartition that has been marked
UNUSABLE, then the
UPDATE statement will fail unless the
SKIP_UNUSABLE_INDEXES session parameter has been set to
See Also:ALTER SESSION for information on the
update_set_clause lets you set column values.
Specify the name of a column of the object that is to be updated. If you omit a column of the table from the
update_set_clause, then the value of that column remains unchanged.
column refers to a LOB object attribute, then you must first initialize it with a value of empty or null. You cannot update it with a literal. Also, if you are updating a LOB value using some method other than a direct
UPDATE SQL statement, then you must first lock the row containing the LOB. See for_update_clause for more information.
column is part of the partitioning key of a partitioned table, then
UPDATE will fail if you change a value in the column that would move the row to a different partition or subpartition, unless you enable row movement. Please refer to the
row_movement_clause of CREATE TABLE or ALTER TABLE.
In addition, if
column is part of the partitioning key of a list-partitioned table, then
UPDATE will fail if you specify a value for the column that does not already exist in the
partition_value list of one of the partitions.
Specify a subquery that returns exactly one row for each row updated.
If you specify only one column in the
update_set_clause, then the subquery can return only one value.
If you specify multiple columns in the
update_set_clause, then the subquery must return as many values as you have specified columns.
If the subquery returns no rows, then the column is assigned a null.
subquery refers to remote objects, then the
UPDATE operation can run in parallel as long as the reference does not loop back to an object on the local database. However, if the
subquery in the
DML_table_expression_clause refers to any remote objects, then the
UPDATE operation will run serially without notification.
You can use the
flashback_query_clause within the subquery to update
table with past data. Please refer to the flashback_query_clause of
SELECT for more information on this clause.
Specify an expression that resolves to the new value assigned to the corresponding column.
DEFAULT to set the column to the value previously specified as the default value for the column. If no default value for the corresponding column has been specified, then the database sets the column to null.
VALUE clause lets you specify the entire row of an object table.
Note:If you insert string literals into a
RAWcolumn, then during subsequent queries, Oracle Database will perform a full table scan rather than using any index that might exist on the
See Also:"Updating an Object Table: Example"
where_clause lets you restrict the rows updated to those for which the specified
condition is true. If you omit this clause, then the database updates all rows in the table or view. Please refer to Chapter 7, "Conditions" for the syntax of
where_clause determines the rows in which values are updated. If you do not specify the
where_clause, then all rows are updated. For each row that satisfies the
where_clause, the columns to the left of the equality operator (=) in the
update_set_clause are set to the values of the corresponding expressions to the right of the operator. The expressions are evaluated as the row is updated.
When operating on a single row, a DML statement with a
returning_clause can retrieve column expressions using the affected row, rowid, and
REFs to the affected row and store them in host variables or PL/SQL variables.
When operating on multiple rows, a DML statement with the
returning_clause stores values from expressions, rowids, and
REFs involving the affected rows in bind arrays.
For each expression in the
RETURNING list, you must specify a corresponding type-compatible PL/SQL variable or host variable in the
expr is restricted as follows:
DELETE statements each
expr must be a simple expression or a single-set aggregate function expression. You cannot combine simple expressions and single-set aggregate function expressions in the same
INSERT statements, each
expr must be a simple expression. Aggregate functions are not supported in an
Single-set aggregate function expressions cannot include the
expr list contains a primary key column or other
NULL column, then the update statement fails if the table has a
UPDATE trigger defined on it.
You cannot specify the
returning_clause for a multitable insert.
You cannot use this clause with parallel DML or with remote objects.
You cannot retrieve
LONG types with this clause.
You cannot specify this clause for a view on which an
OF trigger has been defined.
See Also:PL/SQL User's Guide and Reference for information on using the
COLLECTclause to return multiple values to collection variables
The error_logging_clause has the same behavior in an
UPDATE statement as it does in an
INSERT statement. Please refer to the
INSERT statement error_logging_clause for more information.
UPDATE employees SET commission_pct = NULL WHERE job_id = 'SH_CLERK';
The following statement promotes Douglas Grant to manager of Department 20 with a $1,000 raise:
UPDATE employees SET job_id = 'SA_MAN', salary = salary + 1000, department_id = 120 WHERE first_name||' '||last_name = 'Douglas Grant';
The following statement increases the salary of an employee in the
employees table on the
UPDATE employees@remote SET salary = salary*1.1 WHERE last_name = 'Baer';
The next example shows the following syntactic constructs of the
Both forms of the
update_set_clause together in a single statement
A correlated subquery
where_clause to limit the updated rows
UPDATE employees a SET department_id = (SELECT department_id FROM departments WHERE location_id = '2100'), (salary, commission_pct) = (SELECT 1.1*AVG(salary), 1.5*AVG(commission_pct) FROM employees b WHERE a.department_id = b.department_id) WHERE department_id IN (SELECT department_id FROM departments WHERE location_id = 2900 OR location_id = 2700);
UPDATE statement performs the following operations:
Updates only those employees who work in Geneva or Munich (locations 2900 and 2700)
department_id for these employees to the
department_id corresponding to Bombay (
Sets each employee's salary to 1.1 times the average salary of their department
Sets each employee's commission to 1.5 times the average commission of their department
UPDATE sales PARTITION (sales_q1_1999) s SET s.promo_id = 494 WHERE amount_sold > 1000;
Updating an Object Table: Example The following statement creates two object tables,
people_demo2, of the
people_typ object created in Table Collections: Examples. The example shows how to update a row of
people_demo1 by selecting a row from
CREATE TABLE people_demo1 OF people_typ; CREATE TABLE people_demo2 OF people_typ; UPDATE people_demo1 p SET VALUE(p) = (SELECT VALUE(q) FROM people_demo2 q WHERE p.department_id = q.department_id) WHERE p.department_id = 10;
The example uses the
VALUE object reference function in both the
SET clause and the subquery.
Correlated Update: Example For an example that uses a correlated subquery to update nested table rows, please refer to "Table Collections: Examples".
UPDATE employees SET job_id ='SA_MAN', salary = salary + 1000, department_id = 140 WHERE last_name = 'Jones' RETURNING salary*0.25, last_name, department_id INTO :bnd1, :bnd2, :bnd3;
The following example shows that you can specify a single-set aggregate function in the expression of the returning clause:
UPDATE employees SET salary = salary * 1.1 WHERE department_id = 100 RETURNING SUM(salary) INTO :bnd1;