(Solved) Cannot Delete From A View Postgres Tutorial

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Cannot Delete From A View Postgres

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But you made a left turn on this: CREATE TABLE child_view( id integer, p_data integer, c_data integer ); CREATE RULE "_RETURN" AS ON SELECT TO child_view DO INSTEAD SELECT child.id, p_data, Instead we create one more view CREATE VIEW shoelace_can_delete AS SELECT * FROM shoelace_mismatch WHERE sl_avail = 0; and do it this way: DELETE FROM shoelace WHERE EXISTS (SELECT * FROM I have been in that situation, looking at the log for db A and doing things in db B. In that case, the original query tree does not contain a target list entry for sl_avail, so NEW.sl_avail will get replaced by shoelace_data.sl_avail.

The rule has no rule qualification (discussed later, with the non-SELECT rules, since SELECT rules currently cannot have them) and it is INSTEAD. Does sputtering butter mean that water is present? In fact, the command type is not needed by view rules, but the result relation may affect the way in which the query rewriter works, because special care needs to be How can I debug this? http://stackoverflow.com/questions/5534927/how-to-write-a-delete-rule-on-a-view

Postgres Updatable View

Is it safe to use cheap USB data cables? The parser created the query tree UPDATE shoelace_data SET sl_avail = 6 FROM shoelace_data shoelace_data WHERE shoelace_data.sl_name = 'sl7'; There is a rule log_shoelace that is ON UPDATE with the rule Related 2097UPDATE from SELECT using SQL Server-1how to update a view in postgresql?3What are the benefits of creating an “updatable view” vs a straight insert?2How to add ROW_NUMBER() in a view?0SQL When processing the range table entry for shoelace (the only one up to now) it finds the _RETURN rule with the query tree: SELECT s.sl_name, s.sl_avail, s.sl_color, s.sl_len, s.sl_unit, s.sl_len *

  1. Now we make a final demonstration of the PostgreSQL rule system and its power.
  2. Good reading: depesz.com/index.php/2010/06/15/… –intgr Apr 4 '11 at 14:51 Also: blog.rhodiumtoad.org.uk/2010/06/21/the-rule-challenge –intgr Apr 4 '11 at 14:57 @intgr - Thanks for the links, very helpful.
  3. You want it to be deleted from the table as well.

Join them; it only takes a minute: Sign up Cannot update view? For UPDATE and DELETE, it's still necessary to expand the view query to produce the "old" rows that the command will attempt to update or delete. Any expression using the table's columns, and/or columns of other tables mentioned in USING, can be computed. Postgres Trigger Indeed, according to the PostgreSQL documentation, "Currently, views are read only: the system will not allow an insert, update, or delete on a view.

Views cannot insert new update actions so there is no need to apply update rules to the output of view rewriting. 34.3.1.1. This results in: INSERT INTO shoelace_log VALUES ( *NEW*.sl_name, *NEW*.sl_avail, current_user, current_timestamp ) FROM shoelace_data *NEW*, shoelace_data *OLD*, shoelace_data shoelace_data; In step 2, the rule qualification is added to it, so Note that WHERE CURRENT OF cannot be specified together with a Boolean condition. SQL> create view foobar as select x, y from foo, bar; View created.

You will have to drop the view and everything that depends on it, then re-create it and its dependencies. (The same used to be true for adding a column to a Postgres Update The query trees generated from rule actions are thrown into the rewrite system again, and maybe more rules get applied resulting in more or less query trees. So having two tables t1 and t2 with columns a and b, the query trees for the two statements: SELECT t2.b FROM t1, t2 WHERE t1.a = t2.a; UPDATE t1 SET Here's what happens when I try to use the above rule: >SELECT * FROM child_view; id | p_data | c_data ----+--------+-------- 1 | 1 | 10 2 | 2 | 11

Postgresql Create Rule

I provided links to all that in my answer to your previous post, but here's some more info: updateable views in PostgreSQL 9.1 using INSTEAD OF trigger updateable views (for Pg The substitutions and the added qualifications ensure that, if the original query would be, say, UPDATE shoelace_data SET sl_color = 'green' WHERE sl_name = 'sl7'; no log entry would get written. Postgres Updatable View Nothing in the logs at all. Postgres Rules Why did the best potions master have greasy hair?

So if someone issued the command UPDATE shoelace_data SET sl_avail = 0 WHERE sl_color = 'black'; four rows in fact get updated (sl1, sl2, sl3, and sl4). When an alias is provided, it completely hides the actual name of the table. You can get the effect of an updatable view by creating rules that rewrite inserts, etc. If ONLY is not specified, matching rows are also deleted from any tables inheriting from the named table. Postgresql Views

Can I hint the optimizer by giving the range of an integer? SQL> delete from foobar; delete from foobar * ERROR at line 1: ORA-01752: cannot delete from view without exactly one key-preserved table SQL> delete from foofoo; 1 row deleted. The rewriter uses them to store the access privilege check information that was originally present in the range-table entry that referenced the view. The qualification expressions compare the columns a of both range-table entries for equality.

alias A substitute name for the target table. But the middle SELECT will remain separate from the top, because it contains aggregate functions. See DECLARE for more information about using cursors with WHERE CURRENT OF.

How do you update a view?

The problem that now arises is how to identify the rows to be updated in the view. FROM. There's only one parent tuple per child tuple in this example (my actual schema isn't actually like this of course). This ensures that the actions can see the to-be-updated or to-be-deleted rows; otherwise, the actions might do nothing because they find no rows matching their qualifications.

EDIT: as jmz points out, it would be easier to use a cascading delete than a rule here, but that approach doesn't work for my actual schema. postgresql sql-update sql-view share|improve this question edited Oct 31 '12 at 5:39 Craig Ringer 136k19225316 asked Oct 31 '12 at 5:06 srinu 662413 3 did you even read the first Notes PostgreSQL lets you reference columns of other tables in the WHERE condition by specifying the other tables in the USING clause. Does sputtering butter mean that water is present?

I only have one database, so yes I am connected to it. > > I have the lock file in /tmp: .s.PGSQL.5432.lock > > Should I delete this file? It has an open lock on the table. -- Even a sixth-grader can figure out that you can’t borrow money to pay off your debt -- Sent via pgsql-general mailing list They can lead elegant solutions in ways triggers could not. For simplicity, we'll consider this normalized schema: CREATETABLEhosts( idserialPRIMARYKEY, hostnametextUNIQUE ); CREATETABLEurls( idserialPRIMARYKEY, urltextUNIQUE ); CREATETABLEaccesslog( idserial, visit_timetimestamp, hostintegerREFERENCEShosts, urlintegerREFERENCESurls, refererintegerREFERENCESurls, commenttext ) It would also be nice to create a

Graph Chromatic Number Problem Prove that the following statements for a ring R are equivalent: How do i upgrade my wall sconces Player claims their wizard character knows everything (from books). Does The Amazing Lightspeed Horse work, RAW? How small could an animal be before it is consciously aware of the effects of quantum mechanics? Did you forget the semicolon?

A syntax error?