Is there a way I can select the alias of a SQL Server? For example, I have a server on a box that is named PRODSQL02 but users generally know and connect to this box as PROD.
I have been using ##SERVERNAME but the end recipients of this information don't always understand that PRODSQL02 = PROD.
You can do
SELECT REPLACE(##SERVERNAME, 'SQL02','')
Which removes the 'SQL02' portion of any servername.
You can use substring like this SELECT SUBSTRING(##SERVERNAME, 1, 4) to just get prod out of the value.
Related
I'd like first to know how to make a query over all the databases in my server instance with pymssql (in MSSQL management studio = right click --> new query on the server thumbnail then don't need to specify the name of the db in the query - it just gives you one more column in the output which is the segment from which the record is from). Then how do you do the same as registered servers on two or multiple hosts (I have 2 hosts and I want to pass the same query do I really need to make the two connections ?)
thanks
You could use sp_foreachdb, like this:
EXECUTE master.sys.sp_MSforeachdb 'USE [?]; EXEC update table set foo = bar'
Maybe this can help you (but - to be honest - I did not really understand what you want :-) )
SELECT * FROM sys.databases
I want to know if there is any way to list (get) all the database names on Informix. I need a proper query or stored procedure to do that.
Alternatively you could execute this query when connected to the sysmaster database:
select * from sysdatabases
More to the point (years after the question was posed):
select name from sysmaster:sysdatabases;
According to the documentation, the command to get a list of the databases on the server you are connected to is simply:
show databases
While in Management Studio, I am trying to run a query/do a join between two linked servers.
Is this a correct syntax using linked db servers:
select foo.id
from databaseserver1.db1.table1 foo,
databaseserver2.db1.table1 bar
where foo.name=bar.name
Basically, do you just preface the db server name to the db.table ?
The format should probably be:
<server>.<database>.<schema>.<table>
For example:
DatabaseServer1.db1.dbo.table1
Update: I know this is an old question and the answer I have is correct; however, I think any one else stumbling upon this should know a few things.
Namely, when querying against a linked server in a join situation the ENTIRE table from the linked server will likely be downloaded to the server the query is executing from in order to do the join operation. In the OP's case, both table1 from DB1 and table1 from DB2 will be transferred in their entirety to the server executing the query, presumably named DB3.
If you have large tables, this may result in an operation that takes a long time to execute. After all it is now constrained by network traffic speeds which is orders of magnitude slower than memory or even disk transfer speeds.
If possible, perform a single query against the remote server, without joining to a local table, to pull the data you need into a temp table. Then query off of that.
If that's not possible then you need to look at the various things that would cause SQL server to have to load the entire table locally. For example using GETDATE() or even certain joins. Others performance killers include not giving appropriate rights.
See http://thomaslarock.com/2013/05/top-3-performance-killers-for-linked-server-queries/ for some more info.
SELECT * FROM OPENQUERY([SERVER_NAME], 'SELECT * FROM DATABASE_NAME..TABLENAME')
This may help you.
For those having trouble with these other answers , try OPENQUERY
Example:
SELECT * FROM OPENQUERY([LinkedServer], 'select * from [DBName].[schema].[tablename]')
If you still find issue with <server>.<database>.<schema>.<table>
Enclose server name in []
You need to specify the schema/owner (dbo by default) as part of the reference. Also, it would be preferable to use the newer (ANSI-92) join style.
select foo.id
from databaseserver1.db1.dbo.table1 foo
inner join databaseserver2.db1.dbo.table1 bar
on foo.name = bar.name
select * from [Server].[database].[schema].[tablename]
This is the correct way to call.
Be sure to verify that the servers are linked before executing the query!
To check for linked servers call:
EXEC sys.sp_linkedservers
right click on a table and click script table as select
select name from drsql01.test.dbo.employee
drslq01 is servernmae --linked serer
test is database name
dbo is schema -default schema
employee is table name
I hope it helps to understand, how to execute query for linked server
Usually direct queries should not be used in case of linked server because it heavily use temp database of SQL server. At first step data is retrieved into temp DB then filtering occur. There are many threads about this. It is better to use open OPENQUERY because it passes SQL to the source linked server and then it return filtered results e.g.
SELECT *
FROM OPENQUERY(Linked_Server_Name , 'select * from TableName where ID = 500')
For what it's worth, I found the following syntax to work the best:
SELECT * FROM [LINKED_SERVER]...[TABLE]
I couldn't get the recommendations of others to work, using the database name. Additionally, this data source has no schema.
In sql-server(local) there are two ways to query data from a linked server(remote).
Distributed query (four part notation):
Might not work with all remote servers. If your remote server is MySQL then distributed query will not work.
Filters and joins might not work efficiently. If you have a simple query with WHERE clause, sql-server(local) might first fetch entire table from the remote server and then apply the WHERE clause locally. In case of large tables this is very inefficient since a lot of data will be moved from remote to local. However this is not always the case. If the local server has access to remote server's table statistics then it might be as efficient as using openquery More details
On the positive side T-SQL syntax will work.
SELECT * FROM [SERVER_NAME].[DATABASE_NAME].[SCHEMA_NAME].[TABLE_NAME]
OPENQUERY
This is basically a pass-through. The query is fully processed on the remote server thus will make use of index or any optimization on the remote server. Effectively reducing the amount of data transferred from the remote to local sql-server.
Minor drawback of this approach is that T-SQL syntax will not work if the remote server is anything other than sql-server.
SELECT * FROM OPENQUERY([SERVER_NAME], 'SELECT * FROM DATABASE_NAME.SCHEMA_NAME.TABLENAME')
Overall OPENQUERY seems like a much better option to use in majority of the cases.
I have done to find out the data type in the table at link_server using openquery and the results were successful.
SELECT * FROM OPENQUERY (LINKSERVERNAME, '
SELECT DATA_TYPE, COLUMN_NAME
FROM [DATABASENAME].INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_NAME =''TABLENAME''
')
Its work for me
Following Query is work best.
Try this Query:
SELECT * FROM OPENQUERY([LINKED_SERVER_NAME], 'SELECT * FROM [DATABASE_NAME].[SCHEMA].[TABLE_NAME]')
It Very helps to link MySQL to MS SQL
PostgreSQL:
You must provide a database name in the Data Source DSN.
Run Management Studio as Administrator
You must omit the DBName from the query:
SELECT * FROM OPENQUERY([LinkedServer], 'select * from schema."tablename"')
For MariaDB (and so probably MySQL), attempting to specify the schema using the three-dot syntax did not work, resulting in the error "invalid use of schema or catalog". The following solution worked:
In SSMS, go to Server Objects > Linked Servers > Providers > MSDASQL
Ensure that "Dynamic parameter", "Level zero only", and "Allow inprocess" are all checked
You can then query any schema and table using the following syntax:
SELECT TOP 10 *
FROM LinkedServerName...[SchemaName.TableName]
Source: SELECT * FROM MySQL Linked Server using SQL Server without OpenQuery
Have you tried adding " around the first name?
like:
select foo.id
from "databaseserver1".db1.table1 foo,
"databaseserver2".db1.table1 bar
where foo.name=bar.name
I need to know how to interrogate a Microsoft SQL Server, to see if a given database has been set to Read-Only or not.
Is that possible, using T-SQL?
The information is stored in sys.databases.
SELECT name, is_read_only
FROM sys.databases
WHERE name = 'MyDBNAme'
GO
--returns 1 in is_read_only when database is set to read-only mode.
Querying sys.databases for checking a DB's Read-Only property will only give the right information if the database has been explicitly set to Read-Only mode.
For databases that are in the passive servers (e.g. in AlwaysOn technology Secondary Servers), even though the databases cannot be written into, their Read-Only mode in sys.databases would still be set as False(0).
Hence, it is advisable to check the Read-Only mode of databases using the statement:
SELECT DATABASEPROPERTYEX('MyDBNAme', 'Updateability');
I was trying to use the p.campbell's answer to check if my Azure SQL DB is the primary one or the read only replica - it didn't work. Both the primary DB and the replica returned had 0 on the is_read_only field.
Here's what worked for me:
SELECT DATABASEPROPERTYEX('MyDBNAme', 'Updateability');
the above select statement returns string 'READ_ONLY' or 'READ_WRITE'.
Here is a command to display or set this property.
EXEC sp_dboption "AdventureWorks", "read only"
Sample output
OptionName CurrentSetting
read only OFF
If DB is part of your Always On and the secondary node is designed in Read_Only then
"sys.databases --> Is_Read_Only" column wont show the correct result ! its a bug that Microsoft needs to address it during the next versions.
If you would like to check all DB statuses in your server, use this:
SELECT name, user_access_desc, is_read_only, state_desc, recovery_model_desc
FROM sys.databases;
You can quickly determine your next steps.
I want to get a list of all of the user databases from an mssql server instance. What's the best way to do this?
I know I can select from sys.databases, but I don't see any way to filter out system databases besides hardcoding a list of names to exclude.
I need the script to work on 2000/2005 and 2008.
If the approach I listed above is the only way to go, what are list of names I should exclude? I don't know if 2005 or 2008 added any new system databases off the top of my head.
Was looking in to this again today and decided to profile what Management Studio was doing to populate the Object Explorer details.
Turns out the solution Microsoft have implemented is pretty simplistic and boils down to the following:
SELECT *
FROM master.sys.databases
WHERE Cast(CASE WHEN name IN ('master', 'model', 'msdb', 'tempdb') THEN 1 ELSE is_distributor END As bit) = 0
Please note that this was performed using SSMS 2008R2 (10.50.4033.0).
The first query will return a table with data regarding all of the databases on the instance:
Select *
From sys.databases
From this table you'll notice you can narrow down the scope of data you're looking for by using the WHERE clause. For example, the following queries will essentially return the same result table (the one you're most likely looking for):
Select *
From sys.databases
Where database_id > 5
Select *
From sys.databases
Where len(owner_sid)>1
These queries will work in SQL Server 2008 and 2012.
On SQL Server 2008 R2 Express, looks like I cannot reliably use any of the above methods. INFORMATION_SCHEMA.SCHEMATA only shows me information in the current database, db_id (database_id) #5 is my first user database, and owner_sid on two of my user databases on one of my mirrored databases (running on SQL Server 2008 R2 Standard) shows owner_sid = 1 for my two most recently created databases. (PablolnNZ's comment above is correct: I did not set an explicit owner for those two databases so it still shows as having an owner of 'sa'.)
The only reliable means I was able to use was the following:
SELECT name FROM sys.databases
WHERE name NOT IN ('master', 'model', 'tempdb', 'msdb', 'Resource')
This works in 2005, not 100% sure about the other versions but I think it will fly. It's a bit of a hack but might get you what you need:
select * from sys.databases where len(owner_sid)>1
As nasty as it sounds to hardcode things. The names and number of system databases has been fairly consistent for several versions of SQL. However, if that is too unpleasant you could semi-hardcode them into a table and then plug that into your query.
Not sure if you can offhand. One note -- on 2k you'll have to use master.dbo.sysdatabases and not master.sys.databases (which doesn't exist in 2k).
Starting with SQL Server 2008 you have access to a view called sys.databases which when joined with sys.server_principals can eliminate the databases owned by sa, which you can (most often) safely discern are the "system databases". Thus, allowing you to filter these items out.
select
d.name
,d.database_id
from
sys.databases d
join
sys.server_principals p
on p.sid = d.owner_sid
where
p.name <> 'sa';