Currently, I have some temp tables as this format "#A0089D2C", "#A0232241"
How could I select them to see what are its data?
I tried these queries as below:
Select * from #A0089D2C
Select * from tempdb.dbo.#A0089D2C
But I got the error:
Database name 'tempdb' ignored, referencing object in tempdb.
Database name 'tempdb' ignored, referencing object in tempdb.
Msg 208, Level 16, State 0, Line 1
Invalid object name '#A0089D2C'.
Please advise.
Thanks.
Technically, only that user who created the local temporary table can access it within the scope.
That means, local temporary table (# tables) can be accessed within the same scope by the same user while global temporary table(## tables) can be accessed among all the users until the last user session that references the table disconnects.
you can check table schema via below trick:
Right click on Tempdb database
Task > Export Data
Keep source database as TempDb
Select destination (Remember: you can not transfer data)
On Select source table and view form you will see "Edit mapping". Click on that to see table structure
but if you are really enthusiastic to see data in temporary table then check out this awesome post about viewing another session's Temporary table by Paul White
this should work, at least if the temp-table exists at the moment.
Select * from tempdb.dbo.#A0089D2C
See, temp tables are like the Schrodinger cat, they exists and they don't in the same time ;)
Related
So I have this problem where I need to create an exact copy of another table (schema, indexes) but not the data. We need to temporarily store data before we move it to the table it mirrors.
I can create a mirror table like CREATE TABLE foo_mirror LIKE foo; But I want to automatically update the schema when the schema of the table foo changes'.
I have considered temporary tables as well instead of mirror tables but we will have 2 different processes copying data to the mirror table foo_mirror and copying data to the actual table foo. So I can't use a single session.
So I can compare the schema using the following queries:
-- for_mirror schema
SELECT DISTINCT *
FROM `information_schema`.`columns`
WHERE `TABLE_NAME` LIKE 'foo_mirror'
-- foo schema
SELECT DISTINCT *
FROM `information_schema`.`columns`
WHERE `TABLE_NAME` LIKE 'foo'
I could write some code that will apply updates in a job, or perhaps a trigger. I'm wondering if there is a better way to keep tables in sync or even a tool where I don't need to manage this myself.
I also see a potential problem e.g. Changing the type for a column may fail if data hasn't been updated correctly in the mirror table (string to integer - "one" -> 1).
I am curious if I can insert the data of a table from another connection to a table which i created.
I created the table GPS with the same column-names... etc. in the connection host-abc1.de
and now i want to fill in the data from another table (which also is called GPS and has the same columns, etc.) but this on another connection host-abc2.de
can I do something like this?
INSERT INTO host-abc1.de_NameOfSchema1_GPS, SELECT * FROM host-abc2.de_NameOfSchema2_GPS;
thank you very much for your help
You can create a Linked Server in order to work with data and objects from multiple sources.
The link below gives you detail about how to create a linked server and work with it -
https://learn.microsoft.com/en-us/sql/relational-databases/linked-servers/create-linked-servers-sql-server-database-engine?view=sql-server-ver15
I want be able to debug easily my scripts in Mysql, like in MSSQL (run a chunk of the script then verify the tables and so on), but the temporary tables are not persisted on the server.
For example :
CREATE temporary table a(i int);
INSERT INTO a VALUE (1);
SELECT * FROM a;
If I run the whole script it returns me the right result, but if I run it statement by statement on the insert I get the following error:
SQL.sql: Error (2,13): Table 'test.a' doesn't exist
I suppose this is a server configuration problem.
Temporary tables are dropped when the transaction is over.
from dev.mysql:
Temporary Tables:
You can use the TEMPORARY keyword when creating a
table. A TEMPORARY table is visible only to the current connection,
and is dropped automatically when the connection is closed. This means
that two different connections can use the same temporary table name
without conflicting with each other or with an existing non-TEMPORARY
table of the same name. (The existing table is hidden until the
temporary table is dropped.) To create temporary tables, you must have
the CREATE TEMPORARY TABLES privilege.
Note CREATE TABLE does not automatically commit the current active
transaction if you use the TEMPORARY keyword.
So if you run all these sql in deferent transactions you temporary table wont exist when you run the insert statement.
If these executions are executed in diferent transactions depend on what interface you use. Thats wy if you "run the whole script it returns me the right result" because its all in the same transaction.
You can try to force it to run on the same transaction with:
START TRANSACTION;
<SQL QUERYS>
COMMIT;
anyway i recomend you MySQL Workbench as interface.
my best regards, i hope this help you.
Had created a linked table in MS ACCESS 97. Need to remove the link and make the table static so that, even if the data in backend db is removed or altered, this should not affect the table data in MS Access.
Use a "make table" sql query in order to get the data into a local table then you can delete your linked table, SQL something like:
SELECT * INTO LocalTable FROM LinkedTable
so the code I am working on has this statement executed by PHP (note:This is taken from the PostgreSQL log file so it doesn't include any PHP stuff):
CREATE temporary table IF NOT EXIST temp tablename(id int primary key,
shared int default 0) replace select 1, userid as id
from tablefoo where sharedid = 1337
I don't quite understand what's going on here exactly, I know what a temporary table is, and I can quite accurately guestimate what IF NOT EXIST does, but what is replace doing here? I know replace is like insert but it replaces stuff as well, but in this case, nothing is specified for it to replace with, so does it just replace something with nothing and why the Select 1, I know that pretty much just tells you if your table has rows or something, but what is the point of using it here?
After some research, I found that IF NOT EXIST and replace do not exist in PostgreSQL. Most online sources suggest that SQL functions be used to replace them.
Should I use an SQL function to emulate IF NOT EXIST? If so, what would I write (sorry, I am pretty new to SQL) or should I just use a PHP function.
What about replace?
Sorry for the trouble, thanks for your time, oh and if you guys aren't busy or anything, you could also tell me about how to emulate "ignore", my current solution involves arbitrarily removing it.
Many uses in MySQL for temporary tables can be replaced in PostgreSQL with common table expressions or ordinary subselects.
WITH someCTE AS (
SELECT
...
) SELECT/UPDATE/DELETE ... WHERE sometable.column = someCTE.another_column;
Look into CREATE TABLE documentation. Temporary tables are just as name suggests not permanent:
If specified, the table is created as a temporary table. Temporary
tables are automatically dropped at the end of a session, or
optionally at the end of the current transaction (see ON COMMIT
below). Existing permanent tables with the same name are not visible
to the current session while the temporary table exists, unless they
are referenced with schema-qualified names. Any indexes created on a
temporary table are automatically temporary as well.
In particular temp tables are stored in diffrent (non-public) schema, e.g.:
=> Create Temporary Table someTempTable (value integer);
CREATE TABLE
=> \dt someTempTable
List of relations
Schema | Name | Type | Owner
-----------+---------------+-------+----------
pg_temp_2 | sometemptable | table | postgres
(1 row)
PostgreSQL doesn't have IF NOT EXISTS like in MySQL's CREATE TABLE, so you can't use it. If you want to create some table you need to firstly drop existing one (if it exists). Fortunately you could use SQL command DROP TABLE IF EXISTS to handle this:
=> Drop Table If Exists someTempTable;
DROP TABLE
=> Drop Table If Exists someTempTable;
NOTICE: table "sometemptable" does not exist, skipping
DROP TABLE