SQL/MX 3.2.1 Reference Manual (H06.26+, J06.15+)

SQL/MX Statements
HP NonStop SQL/MX Release 3.2.1 Reference Manual—691117-005
2-164
DELETE Statement
column-name. A scalar subquery in expression cannot refer to the
table being updated.
If expression refers to columns being updated, NonStop SQL/MX uses
the original values to evaluate the expression and determine the new
value.
See Expressions on page 6-41.
WHERE search-condition
specifies a search condition that selects rows to delete. Within the search
condition, any columns being compared are columns in the table or view being
deleted from. See Search Condition on page 6-108.
If you do not specify a search condition, all rows in the table or view are deleted.
You can also delete all the rows from a table or a partition of a table by using the
PURGEDATA utility.
WHERE rowset-search-condition
specifies an array of search conditions that selects rows to delete. The search
conditions are applied successively and rows selected by each condition are
deleted before the next search condition is applied. See Rowset Search Condition
on page 6-110.
[FOR] access-option ACCESS
specifies the access option required for data used in the evaluation of the search
condition. See Data Consistency and Access Options on page 1-8.
READ COMMITTED
specifies that any data used in the evaluation of the search condition must
come from committed rows.
SERIALIZABLE | REPEATABLE READ
specifies that the DELETE statement and any concurrent process (accessing
the same data) execute as if the statement and the other process had run
serially rather than concurrently.
SKIP CONFLICT
enables transactions to skip rows locked in a conflicting mode by another
transaction. The rows under consideration are the result of evaluating the
search condition for the DELETE statement. SKIP CONFLICT cannot be used
in a SET TRANSACTION statement.
The default access option is the isolation level of the containing transaction, which
is determined according to the rules specified in Isolation Level
on page 10-56.
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