Some Useful SQL queries

I have compiled below some SQL queries that I have been using regularly. I can’t take credit for writing all of them, though.

/*get size and free space in a database*/
SELECT DB_NAME() AS DbName,
name AS FileName,
size/128.0 AS CurrentSizeMB,
size/128.0 – CAST(FILEPROPERTY(name, ‘SpaceUsed’) AS INT)/128.0 AS FreeSpaceMB
FROM sys.database_files;

/*Get size of the database.*/
SELECT DB_NAME(database_id) AS DatabaseName,
Name AS Logical_Name,
Physical_Name, (size*8)/1024 SizeMB
FROM sys.master_files
GO

/*Find which processes are blocking on the Sql Server.*/
select * from master.dbo.sysprocesses (nolock) where blocked 0 and spid blocked
Execute DBCC inputbuffer

/*Find blocking SPID*/
select distinct object_name(a.rsc_objid), a.req_spid, b.loginame
from master.dbo.syslockinfo a (nolock) join
master.dbo.sysprocesses b (nolock) on a.req_spid=b.spid
where object_name(a.rsc_objid) is not null

/*Disable All SQL Server Agent Jobs*/
USE MSDB;
GO
UPDATE MSDB.dbo.sysjobs
SET Enabled = 0
WHERE Enabled = 1;
GO

/*Enable All SQL Server Agent Jobs*/
USE MSDB;
GO
UPDATE MSDB.dbo.sysjobs
SET Enabled = 1
WHERE Enabled = 0;
GO

/*Disable Jobs By Job Name*/
USE MSDB;
GO
UPDATE MSDB.dbo.sysjobs
SET Enabled = 0
WHERE [Name] LIKE ‘%Jobname%’;
GO

/*Disable Jobs By Job Category*/
USE MSDB;
GO
UPDATE J
SET J.Enabled = 0
FROM MSDB.dbo.sysjobs J
INNER JOIN MSDB.dbo.syscategories C
ON J.category_id = C.category_id
WHERE C.[Name] = ‘Database Maintenance’;
GO

/*Find out SQL version in SQL 2000 and above.*/
SELECT ‘SQL Server ‘
+ CAST(SERVERPROPERTY(‘productversion’) AS VARCHAR) + ‘ – ‘
+ CAST(SERVERPROPERTY(‘productlevel’) AS VARCHAR) + ‘ (‘
+ CAST(SERVERPROPERTY(‘edition’) AS VARCHAR) + ‘)’

/*Find out version of sql in 2008.*/
SELECT SERVERPROPERTY(‘productversion’), SERVERPROPERTY (‘productlevel’), SERVERPROPERTY (‘edition’)

/*Mirror is failed and cannot drop database. Database shows in recovery mode. Refer the following link: */
http://www.sqlnewsgroups.net/sqlserver/t20474-database-mirroring-problems-cant-drop-database.aspx

alter database dbname set partner off
drop database dbname

/*update statistics on all the tables:*/
Exec sp_MSForEachtable ‘UPDATE STATISTICS ? WITH FULLSCAN’
GO

/*Get the table having the biggest,largest,huge size:*/

USE DBNAME
GO
CREATE TABLE #temp (
table_name sysname ,
row_count INT,
reserved_size VARCHAR(50),
data_size VARCHAR(50),
index_size VARCHAR(50),
unused_size VARCHAR(50))
SET NOCOUNT ON
INSERT #temp
EXEC sp_msforeachtable ‘sp_spaceused ”?”’
SELECT a.table_name,
a.row_count,
COUNT (*) AS col_count,
a.data_size
FROM #temp a
INNER JOIN information_schema.columns b
ON a.table_name collate database_default
= b.table_name collate database_default
GROUP BY a.table_name, a.row_count, a.data_size
ORDER BY CAST(REPLACE(a.data_size, ‘ KB’, ”) AS integer) DESC
DROP TABLE #temp

/*Another query for largest tables*/
declare @id int
declare @type character(2)
declare @pages int
declare @dbname sysname
declare @dbsize dec(15,0)
declare @bytesperpage dec(15,0)
declare @pagesperMB dec(15,0)

create table #spt_space
(
objid int null,
rows int null,
reserved dec(15) null,
data dec(15) null,
indexp dec(15) null,
unused dec(15) null
)

set nocount on

— Create a cursor to loop through the user tables
declare c_tables cursor for
select id
from sysobjects
where xtype = ‘U’

open c_tables

fetch next from c_tables
into @id

while @@fetch_status = 0
begin

/* Code from sp_spaceused */
insert into #spt_space (objid, reserved)
select objid = @id, sum(reserved)
from sysindexes
where indid in (0, 1, 255)
and id = @id

select @pages = sum(dpages)
from sysindexes
where indid < 2
and id = @id
select @pages = @pages + isnull(sum(used), 0)
from sysindexes
where indid = 255
and id = @id
update #spt_space
set data = @pages
where objid = @id

/* index: sum(used) where indid in (0, 1, 255) – data */
update #spt_space
set indexp = (select sum(used)
from sysindexes
where indid in (0, 1, 255)
and id = @id)
– data
where objid = @id

/* unused: sum(reserved) – sum(used) where indid in (0, 1, 255) */
update #spt_space
set unused = reserved
– (select sum(used)
from sysindexes
where indid in (0, 1, 255)
and id = @id)
where objid = @id

update #spt_space
set rows = i.rows
from sysindexes i
where i.indid = 0)
BEGIN
–Dump the results of the sp_spaceused query to the temp table
INSERT #TempTable
EXEC sp_spaceused @TableName

–Get the next table name
FETCH NEXT FROM tableCursor INTO @TableName
END

–Get rid of the cursor
CLOSE tableCursor
DEALLOCATE tableCursor

–Select all records so we can use the reults
SELECT *
FROM #TempTable

–Final cleanup!
DROP TABLE #TempTable

GO
The above is the actual stored procedure, this must be created first then you simply call this one procedure to get the list of tables and sizes. At the bottom of this article you will find a zip file available for download that will include this script file.

Usage

Now to get the table sizes for the current database you can simply run the following command.

EXEC GetAllTableSizes
The results of this procedure execution will show you the number of rows and physical sizes of each user defined table in your database.
*******************************************************************************************************************************************
/*How to take a TRANSACTION LOG Backup:*/
BACKUP LOG Logname TO DISK = ‘C:\Backup\Logname.trn’
sp_spaceused
DBCC SQLPERF(logspace)
DBCC OPENTRAN

/*Show blocking spids:*/
select c=sql_text.text, spid,blocked,waittime,cpu,physical_io, memusage, hostname, login_time, last_batch from master.dbo.sysprocesses
cross apply sys.dm_exec_sql_text(sql_handle) as sql_text
where hostname ”
order by blocked desc

/*Find out longest running queries on a SQL server.*/
SELECT DISTINCT TOP 10
t.TEXT QueryName,
s.execution_count AS ExecutionCount,
s.max_elapsed_time AS MaxElapsedTime,
ISNULL(s.total_elapsed_time / s.execution_count, 0) AS AvgElapsedTime,
s.creation_time AS LogCreatedOn,
ISNULL(s.execution_count / DATEDIFF(s, s.creation_time, GETDATE()), 0) AS FrequencyPerSec
FROM sys.dm_exec_query_stats s
CROSS APPLY sys.dm_exec_sql_text( s.sql_handle ) t
ORDER BY
s.max_elapsed_time DESC
GO
*************************************************************************************
Prior to SQL Server 2005, blocking could be detected using the sp_blocker_pss80 stored procedure, sp_who2, Perfmon and SQL Profiler. However, SQL Server 2005 has added some important new tools that adds to this toolkit. These tools include:
•Enhanced System Monitor counters (Perfmon)
•DMV’s: sys.dm_os_wait_stats, sys.dm_os_waiting_tasks and sys.dm_tran_locks
•Blocked Process Report in SQL Trace
•SQLDiag Utility
*************************************************************************************
/*Find all user logins in a database*/
use dbname
select loginname from syslogins
*************************************************************************************
/*Check the owner of a database*/
select suser_sname(owner_sid) from sys.databases
*************************************************************************************
/*Change the owner of a database*/
EXEC sp_changedbowner ‘Parag’
*************************************************************************************
/*Query to find relationship between tables*/
Select
object_name(rkeyid) Parent_Table,
object_name(fkeyid) Child_Table,
object_name(constid) FKey_Name,
c1.name FKey_Col,
c2.name Ref_KeyCol
From
sys.sysforeignkeys s
Inner join sys.syscolumns c1
on ( s.fkeyid = c1.id And s.fkey = c1.colid )
Inner join syscolumns c2
on ( s.rkeyid = c2.id And s.rkey = c2.colid )
Order by Parent_Table,Child_Table
*************************************************************************************
/*How to find if transcation logs are being restored*/
select distinct r.destination_database_name, r.restore_date,
bs.server_name, m.physical_device_name as backup_device, b.physical_name
from msdb.dbo.restorehistory r
inner join msdb.dbo.backupfile b on r.backup_set_id = b.backup_set_id
inner join msdb.dbo.backupset bs on b.backup_set_id = bs.backup_set_id
inner join msdb.dbo.backupmediafamily m on bs.media_set_id = m.media_set_id
*************************************************************************************
/*Increase mirror Timeout*/
ALTER DATABASE dbName SET PARTNER TIMEOUT 20
*************************************************************************************
/*Check when a table was last updated*/
select object_name(OBJECT_ID) as dbname,last_user_update,* from sys.dm_db_index_usage_stats

/*Script to find last run queries*/
SELECT deqs.last_execution_time AS [Time], dest.TEXT AS [Query]
FROM sys.dm_exec_query_stats AS deqs
CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest
ORDER BY deqs.last_execution_time DESC
*************************************************************************************
/*find if a column is present in all the tables in a database.*/
USE AdventureWorks
GO
SELECT t.name AS table_name,
SCHEMA_NAME(schema_id) AS schema_name,
c.name AS column_name
FROM sys.tables AS t
INNER JOIN sys.columns c ON t.OBJECT_ID = c.OBJECT_ID
WHERE c.name LIKE ‘%EmployeeID%’
ORDER BY schema_name, table_name;
*************************************************************************************
/*Find all columns in a table*/
SELECT * FROM sys.columns WHERE object_id = OBJECT_ID(‘dbo.tablename’)
*************************************************************************************
/*Using loop in SQL.*/
Declare @loop int
set @loop = 1
select @loop
while (@loop != 5)
begin
–Put your query here.
set @loop = @loop+1
end
*************************************************************************************
/*Using charindex and patindex*/
USE AdventureWorks2012;
GO
DECLARE @document varchar(64);
SELECT @document = ‘Reflectors are vital safety’ +
‘ components of your bicycle.’;
SELECT CHARINDEX(‘bicycle’, @document); — Gives the number where the character is found
GO
*************************************************************************************
/*Using substring to return part of a string*/
–SUBSTRING ( expression ,start , length )
USE AdventureWorks2012;
GO
SELECT LastName, SUBSTRING(FirstName, 1, 1) AS Initial
FROM Person.Person
WHERE LastName like ‘Barl%’
ORDER BY LastName;

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About parag waghmare

I am working on the Windows technologies for a long time now. Primarily working as a Service Engineer on System Center products. Right now on System Center 2012 and Windows Server 2012. I have worked extensively on MOM 2005 to SCOM 2007 migrations and SCOM 2007 to SCOM 2012 migrations.
This entry was posted in Microsoft SQL Server and tagged , . Bookmark the permalink.

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