I've got a problem with a database here, in which after one update on the database one table stopped working.
What i can't do (Considering table xxx):
Dump whole database; (it says that the table doesn't exist)
SELECT *
FROM xxx; (it says that the table doesn't exist)
CREATE TABLE xxx(id int); (it says that the table exists)
I can't find any solution on the internet.
The Table Appears when you do a show tables?
mysql> show tables
Have you tried restart the mysql service?
Related
In SQL Server Database Engine I have a table named Table A.
I deleted the table using graphical interface, but when I wanted to create a table with same name, the error shows
The object already exists
What is the remedy of this situation?
The following steps should help you track down what is going on and help you create your table:
Right-click on your database and select refresh
Verify that your table does not exist under this database.
If you table is
not shown here, then very likely your table is displayed under the
master database.
To create a table in your selected database,
first select the database and then run your query.
A better
option for number 4, just to be sure you are specifying the correct
database is to run the command use dbname; (where dbname is
the name of your database). Do this on the line above your create table code.
This is a really strange question. I have a dynamic SQL stored procedure that inserts data into a static table in the queried database. This table is referenced quite a lot in the query. So when I needed to change this table and add two new columns I deleted it and used the import wizard (Excel spread sheet) to create a new one and gave it that same name, so I didn't have to amend the SP. The SP works fine, however I also have this query outside of dynamic SQL and when I run it, it now fails.
At first I couldn't work out why but when I saw that it was failing on the INSERT INTO the newly created (but with the same name) table because there were too many columns to match the table. I ran a simple SELECT * FROM and it brought back the old table with the 3 columns it used to have and not the new table with 5 columns?
How can this table still exist if its been deleted? Its like a ghost table still remains?
Thanks
First check your temp table exists or not in your database.IF exists means drop your temp table and then create new one.
IF EXISTS(SELECT 1 FROM tempdb.dbo.sysobjects WHERE xtype in ('U') AND id =
object_id(N'tempdb..#your_tableName') )
DROP TABLE #your_tableName;
This is known behaviour with views and can be fixed by dropping and recreating the view. Not sure why it is acting the same way for a table. Possibilities I can think of -
It is a view
The new table was not created in the same database
Try dropping and recreating the sproc, for what it is worth
I've just had something very strange happen to me with a Firebird database.
I was trying to create a table, and the CREATE TABLE failed for some reason. But now it's stuck in a very strange state:
If I try to CREATE TABLE again with the same table name, it gives an error: the table already exists. But if I try to DROP TABLE that table, it gives an error: the table does not exist. Trying to SELECT * FROM that table gives the "table does not exist" error, and the name does not show up in the metadata query:
SELECT RDB$RELATION_NAME
FROM RDB$RELATIONS
WHERE RDB$SYSTEM_FLAG=0
So for some reason, the table really seems to not be there, but I can't create it because something somewhere indicates that it does exist.
Does anyone have any idea how to fix this? I've already tried closing all connections to that database, which has helped with inconsistency issues in the past, but this time it doesn't help.
You didn't give details about what was the error when you tried to create the table, so I cannot comment it. But RDB$RELATIONS is not the only system table affected when you create a table. Maybe you are now in an inconsistent situation where some information about that table exists in some system tables and doesn't exists in others.
Another option is corrupted indexes in the system tables, so the record is not there but the index think it still exists.
Try to do a backup/restore and see if it helps. It it doesnt work, try to search for records related to that "non created" table in the other system tables (RDB$RELATION_FIELDS, etc) and if you find any, try to delete them.
As a last option, you may create a new clean database with correct metadata and pump your data to it using IBDataPump.
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.
I am trying to insert data from one table to another with same structure,
select * into tbltable1 from tbltable1_Link
I am getting the following error message:
There is already an object named 'tbltable1' in the database.
The SELECT INTO statement creates a new table of the name you provide and populates it with the results of the SELECT statement.
I think you should be using INSERT INTO since the table already exists. If your purpose is in fact to populate a temporary table, then you should provide a table name that does not already exist in the database.
See MSDN for more information on this.
If you are confident that tbltable1 is not required, you can drop the table first.
You may also want to consider using temporary tables...
Select * into ##MyTemporaryTable FROM tblTable1_Link
You can then use the temporary table in this session. (Ending the session should drop the temporary table automatically, if I remember correctly. It's been a while since I've worked with SQL Server).