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STREAM (table)
updates a continuous data stream from the specified table. You cannot specify STREAM
access for the UPDATE statement if it is not embedded as a table reference in a SELECT
statement. See
"SELECT Statement" (page
[AFTER LAST ROW]
causes the stream to skip all existing rows in the table and update only rows that are
published after the stream's cursor is opened.
set-clause
associates a value with a specific column in the table being updated. For each set-clause,
the value of the specified target column-name is replaced by the value of the update source
expression (or NULL). The data type of each target column must be compatible with the
data type of its source value.
In addition, the SET clause allows multiple columns to be specified on the left side of the
assignment operator. These columns are updated using multiple values specified on the right
side of the assignment operator. Multiple sets of multiple columns could also be specified.
The right side of the assignment operator could be simple values or a subquery. Only one
subquery could be specified on the right side of a SET statement.
column-name
names a column in table to update. You cannot qualify or repeat a column name. You
cannot update the value of a column that is part of the primary key.
expression
is an SQL value expression that specifies a value for the column. The expression cannot
contain an aggregate function defined on a column. The data type of expression must
be compatible with the data type of column-name.
If expression refers to columns being updated, Neoview SQL uses the original values
to evaluate the expression and determine the new value.
See
"Expressions" (page
NULL
can also specify the value of the update source.
SET ON ROLLBACK set-roll-clause [,set-roll-clause]...
causes one or more columns to be updated when the execution of the UPDATE statement
causes its containing transaction to be rolled back.
set-roll-clause
sets the specified column to a particular value. For each set-roll-clause, the value
of the specified target column-name is replaced by the value of the update source
expression. The data type of each target column must be compatible with the data
type of its source value.
column-name
names a column in table to update. You cannot qualify or repeat a column name.
You cannot update the value of a column that is part of the primary key.
expression
is an SQL value expression that specifies a value for the column. expression cannot
contain an aggregate function defined on a column. The data type of expression
must be compatible with the data type of column-name.
If expression refers to columns being updated, Neoview SQL uses the original
values to evaluate the expression and determine the new value.
See
"Expressions" (page
164).
255).
255).
UPDATE Statement
199
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