I have to run a script for a company. I just get the same error every time.
The query:
DELETE FROM WMO
WHERE (clientnr = ****** AND number_message = *****)
The error:
ORA-01752: cannot delete from view without exactly one key-preserved
table
What did I wrong?
Thnx!
Database views are in general projection of one or more tables. It is a SELECT statement over one or more tables to be specific. For database engine it is impossible to decide what it should delete and from which table unless the view is constructed from single table.
The best solution is to run DELETE command against tables that are used to construct the view.
Additional information:
ORA-01752: cannot delete from view without exactly one key-preserved table
I have a table called TableA in DatabaseA and I want to create the same TableA in DatabaseB. I am able to do so but copying only the structure and the data, I seem unable to also create the primary keys and indexes. Is there an SQL statement I can use that copies the table structure, the table data, the primary keys and indexes please?
I am using Oracle 11G.
1. First Method
To get tables and indexes without data see following post
Stack Post
after creating table you can load data using
insert into dest_table as select * from source_table
2. Second Method
use expdp to take backup of source table using table=yourtable parameter as this will by default will take indexes and when you will import using impdp on destination database it will automatically rebuild those indexes.
I have sql Upgrade script which has many sql statements(DDL,DML). When i ran this upgrade script in SQL developer, it runs successufully.I also provide in my script at the bottom commit. I can see all the changes in the database after running this upgrade script except the unique index constraints. When i insert few duplicate records it says unique constraint violated. It means the table has unique constraints. But i dont know why i cant view this constraints in oracle sql developer. The other DDL changes made i can view.I dont know is there any settings to view it in oracle sql developer.
CREATE UNIQUE INDEX "RATOR_MONITORING"."CAPTURING_UK1" ON "RATOR_MONITORING"."CAPTURING" ("DB_TABLE");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND" ("NAME");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_BUSINESS_PROCESS_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND_BUSINESS_PROCESS" ("BRAND_ID", "BP_ID");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_ENGINE_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND_ENGINE" ("BRAND_ID", "ENGINE_ID");
As A Hocevar noted, if you create an index
create unique index test_ux on test(id);
you see it in the Indexes tab of the table properties (not in the Constraints tab).
Please note that COMMIT is not required here, it is done implicitely in each DDL statement. More usual source of problems are stale metadata in SQL Developer, i.e. missing REFRESH (ctrl R on user or table node).
If you want to define the constraint, add following statement, that will reuse the index defined previously
alter table test add constraint test_unique unique(id) using index test_ux;
See further discussion about the option in Documentation
I am assuming you are trying to look for index on a table in the correct tab in sql developer. If you are not able to see the index there, one reason could be that your user (the one with which you are logged in) doesn't have proper rights to see the Index.
If you not obtain any error, the solution is very simple and tedious. SQL Developer doesn't refresh his fetched structures. Kindly push Refresh blue icon (or use Ctrl-R) in Connections view or disconnect and connect again (or restart SQL Developer) to see your changes in structures.
I have a table with a foreign key type which links to table wp_types. Whenever I try and insert a row into that table I get the error:
ERROR: permission denied for schema base
LINE 1: SELECT 1 FROM ONLY "base"."wp_types" x WHERE "id" OPERATOR(p...
^
QUERY: SELECT 1 FROM ONLY "base"."wp_types" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x
The query is being executed as postgres.
Also I do not understand what this query is trying to do, it is clearly linked with checking the foreign key constraints but I don't understand how.
From postgresql docs:
If ONLY is specified, only that table is scanned. If ONLY is not specified, the table and all its descendant tables (if any) are scanned.
As you mentioned error is connected with checking foreign keys. When ONLY is specified postgres can not check them and it may cause an error.
Two points:
Is it possible you dropped the superuser permissions from the postgres user?
What are the permissions for the base schema?
Now one thing to consider is that you aren't sure what the query is doing. A simple EXPLAIN can show you what it is doing, but the error suggests the problem is with schema permissions, not with what the query is doing.
Try:
GRANT USAGE ON SCHEMA base TO postgres;
I am migrating an MS Access application (which has linked tables to a MSSQL Server) to MySQL.
As a means to overcome some MSAccess table naming problems, I am seeking a solution to add a MySQL table alias that will point to an existing table in the MySQL database. Ideally I would like to create the alias 'dbo_customers' in mysql that would point to the customers table also in mysql.
To be clear I am not wanting to alias a table name inside a query like this:
SELECT * FROM customers AS dbo_customers
But rather I would like to be able issue the following query:
SELECT * FROM dbo_customers
and have it return data from the customers table.
Off the top of my head
CREATE VIEW dbo_customers AS
SELECT * FROM customers
Maybe not the best solution but should work as the view is updatable. Will definitely work for Read Only
You can create a View.
CREATE VIEW dbo_customers AS SELECT * FROM customers;
If that doesn't work for you, you could try creating a shadow-copy of the table, and use Triggers to keep the tables synced.
For example:
CREATE TABLE t1( id serial primary key, field varchar(255) not null );
CREATE TABLE dbo_t1( id serial primary key, field varchar(255) not null );
-- INSERT trigger
CREATE TRIGGER t1_dbo_insert AFTER INSERT ON t1
FOR EACH ROW BEGIN
INSERT INTO dbo_t1 SET field = NEW.field;
-- No need to specify the ID, it should stay in-sync
END
-- UPDATE trigger
CREATE TRIGGER t1_dbo_update AFTER UPDATE ON t1
FOR EACH ROW BEGIN
UPDATE dbo_t1 SET field = NEW.field WHERE id = NEW.id;
END
-- DELETE trigger
CREATE TRIGGER t1_dbo_delete AFTER DELETE ON t1
FOR EACH ROW BEGIN
DELETE FROM dbo_t1 WHERE id = OLD.id;
END
Not exactly an 'alias', and far from perfect. But it is an option if all else fails.
there is a simpler solution for MySQL via MERGE table engine:
imagine we have table named rus_vacancies and need its English equivalent
create table eng_vacancies select * from rus_vacancies;
delete from eng_vacancies;
alter table eng_vacancies ENGINE=MERGE;
alter table eng_vacancies UNION=(rus_vacancies);
now table rus_vacancies equals to table eng_vacancies for any read-write operations
one limitation - original table must have ENGINE=MyISAM (it can be easily done by "alter table rus_vacancies ENGINE=MyISAM")
You could create a view named dbo_customers which is backed by the customers table.
#OMG Ponies ponies said in a comment:
Why not rename the table?
...and it seems the obvious answer to me.
If you create an ODBC linked table for the MySQL table customers it will be called customers and then all you have to do is rename the table to dbo_customers. There is absolutely no need that I can see to create a view in MySQL for this purpose.
That said, I'd hate to have an Access app that was using SQL Server table names when the MySQL tables were not named the same thing -- that's just confusing and will lead to maintenance problems (i.e., it's simpler for the linked tables in the Access front end to have the same names as the MySQL tables, wherever possible). If I were in your position, I'd get a search and replace utility and replace all the SQL Server table names with the MySQL table names throughout the entire Access front end. You'd likely have to do it one table at a time, but in my opinion, the time it takes to do this now is going to be more than made up for in clarity going forward with development of the Access front end.
I always rename my "linked to SQL" tables in Access from
{dbo_NAME} to {NAME}.
The link creates the table name as {dbo_NAME} but access occasionally has problems with the dbo_ prefix.
Aliases would be nice, yet MySQL does NOT have such a feature.
One option that may serve your needs, besides creating a view, is to use the FEDERATED storage engine locally.
CREATE TABLE dbo_customers (
id INT(20) NOT NULL AUTO_INCREMENT,
name VARCHAR(32) NOT NULL DEFAULT '',
PRIMARY KEY (id),
)
ENGINE=FEDERATED
DEFAULT CHARSET=latin1
CONNECTION='mysql://fed_user#localhost:9306/federated/customers';
There are currently some limitations with the FEDERATED storage engine. Here are a couple especially important ones:
FEDERATED tables do not support transactions
FEDERATED tables do not work with the query cache
I'd like to mention a bad solution I explored (and abandoned), which was to use hardlinks on the .frm, .MYD and .MYI files corresponding to my table in /var/lib/mysql/{name_of_my_database}/.
It does, however, NOT work. For InnoDB tables, it simply cannot (even if you hardlink the .idb file) because tables are also referenced in ibdata1.
For MyISAM tables, it kind of works, except it doesn't because in memory, the tables are still distinct and thus do not share cache. So if you write a row to original_table, it won't immediately appear in aliased_table. You would have to flush tables first… which defeats the purpose and even causes data loss (if you insert a row in both the original and the alias before flushing, only one row is kept).
I thought my experiment was worth mentioning as a cautionary tale.