In following example we will go through the statements used in SQL Server 200 T-SQL, SQL Server 2005 T-SQL, SQL Server 2008 T-SQL to insert multiple rows by using single insert statement.
--For SQL server 2000 and Above USE DBName GO INSERT INTO MyTable (col1, col2) VALUES ('FirstValue',1) INSERT INTO MyTable (col1, col2) VALUES ('SecondValue',2) INSERT INTO MyTable (col1, col2) VALUES ('ThirdValue',3) INSERT INTO MyTable (col1, col2) VALUES ('FourthValue',4) INSERT INTO MyTable (col1, col2) VALUES ('FifthValue',5) GO -- For SQL Server 2005 and Above USE DBName GO INSERT INTO MyTable (col1, col2) SELECT 'FirstValue' ,1 UNION ALL SELECT 'SecondValue' ,2 UNION ALL SELECT 'ThirdValue' ,3 UNION ALL SELECT 'FourthValue' ,4 UNION ALL SELECT 'FifthValue' ,5 GO -- For SQL Server 2008 and Above USE DBName GO INSERT INTO MyTable (col1, col2) VALUES ('FirstValue',1), ('SecondValue',2), ('ThirdValue',3), ('FourthValue',4), ('FifthValue',5) GO
-- Create PKey constrainton existing column ALTER TABLE TableName ADD CONSTRAINT PKeyName PRIMARY KEY CLUSTERED (PKeyColumn) GO -- Create Fkey Constraint ALTER TABLE FKeyTable ADD CONSTRAINT FKeyName FOREIGN KEY (FKeyColumn) REFERENCES PKeyTable (PKeyColumn) ON UPDATE NO ACTION ON DELETE NO ACTION GO -- Create check constraint ALTER TABLE TableName WITH NOCHECK ADD CONSTRAINT ConstraintName CHECK ( ConstraintExpression) GO -- Create Unique key constraint ALTER TABLE TableName ADD CONSTRAINT UKeyName UNIQUE NONCLUSTERED (col1,col2) GO -- Craete clustered/non clustered index CREATE CLUSTERED INDEX IndexName ON TableName (ColumnsHere) ON [PRIMARY] GO --Retreive data from excel file select [Server], [Orphaned Logins] FROM OPENDATASOURCE('Microsoft.Jet.OLEDB.4.0', 'Data Source= 'Path here';Extended Properties=Excel 8.0')...[Sheet1$] order by [Orphaned Logins] asc -- Info about locks sp_lock SELECT * FROM sys.dm_tran_locks SELECT * FROM sys.dm_exec_requests -- Track active trans on SQL Server 2005 or 2008 SELECT * FROM sys.dm_tran_session_transactions ---------List columns in table SELECT Column_Name, Data_Type FROM information_schema.columns WHERE table_name = 'authors' ----Current Connections to a DB SELECT hostname, program_name,loginame, cpu, physical_io, memusage, login_time, last_batch, [status] FROM master.dbo.sysprocesses WHERE db_name(dbid) = 'DBNameHere' ORDER BY hostname -- identify longest open transaction DBCC OPENTRAN('DBNameHere') GO -- get info about object sp_help ObjectNameHere -- Get list of all table valued UDF in DB SELECT name, crdate FROM sys.sysobjects WHERE XTYPE = 'U' --AF = Aggregate function (CLR) --C = CHECK constraint --D = Default or DEFAULT constraint --F = FOREIGN KEY constraint --L = Log --FN = Scalar function --FS = Assembly (CLR) scalar-function --FT = Assembly (CLR) table-valued function --IF = In-lined table-function --IT = Internal table --P = Stored procedure --PC = Assembly (CLR) stored-procedure --PK = PRIMARY KEY constraint (type is K) --RF = Replication filter stored procedure --S = System table --SN = Synonym --SQ = Service queue --TA = Assembly (CLR) DML trigger --TF = Table function --TR = SQL DML Trigger --TT = Table type --U = User table --UQ = UNIQUE constraint (type is K) --V = View --X = Extended stored procedure
Suppose you have two dates and you are required to get difference in following form
00 years, 00 months and 00 days.
Normally we may get year, month, days etc alone through
datediff(yy/mm/dd, firstDate, secondDate) function. But in this case we are required to get Year, month and days difference is required together.
So get date in above format use following T-SQL script
SELECT '2007-04-25' as [FirstDate], getdate() as [SecondDate], CONVERT(varchar(6),datediff(yy,'2007-04-25',getdate())) + ' Years, '+ CONVERT(varchar(4),datediff(mm, '2007-04-25',getdate())%12)+ ' Months and '+ CONVERT(varchar(4),datediff(dd, '2007-04-25',getdate())%30)+ ' Days' as [RequiredDifference] GO
SELECT 1 UNION SELECT NULL UNION SELECT '1'
Answer: NULL, 1
Explanation: UNION only takes distinct values and ‘1’ is implicitly converted to 1. So the NULL comes first and then 1 comes.
Ref: Union –
Note: The Question of day is taken from SQLServercentral.com. I want to compile selected QOD.
During the early days when i planned to permanently enter into Database Administration field, i searched a lot of preliminary books and code snippets. As T-SQL is core of SQL Server DBA, i spend most of time to cover the concepts and to gain as much skill as possible. During that time i prepared some code refreshers that i usually consulted later for practice of T-SQL. So primarily following code and explanation is for beginners and field switchers those want to strat careers in Database Administration. Most of concepts here will be helpful in iinterview questions and day to day T-SQL paradigm. I will try to update this post later also when required.
Code used here is run under pubs database and is compatible to SQL Server 2000 and SQL Server 2005.
Select 'Wellcome to T-SQL'
Concatenation and alias
Concatenation is done using ‘+’. Alias is also used in two ways. Alias can be used in ‘select’ and ‘from’ statement
USE pubs GO SELECT au_fname+au_lname fullName, [STATE]+','+zip AS location FROM authors auth
Here in above script concatenation is used in select list. Alias is used in select list (fullname) and in from clause (auth)
Comparison on string data
Comparison operators can also be used with text/string data
SELECT [STATE] FROM authors WHERE [STATE] > 'ma'
Above script will compare the given strings according to alphabetical order. It will return states that start with alphabets after ma.
IN operator may be used instead of multiple OR
SELECT au_fname,au_lname, [STATE] FROM authors WHERE STATE IN ('TN','OR','MI','MD')
Between operator may be used instead of > and <>
SELECT price FROM titles WHERE price BETWEEN 10 AND 20
T-SQL uses two wild cards
‘%’ is used multiple match and ‘_’ is used for single char match
SELECT au_fname, au_lname FROM authors WHERE au_fname LIKE 'Abr%'
Above script will look for names with Abr as first three characters and any characters after these three chars.
SELECT au_fname, au_lname FROM authors WHERE au_fname LIKE 'Ab_aham'
Above script will look for names starting with Ab and ending with aham, and any character there in place of _.
If we have to find % inside data, then use escape character. Normally @ is used
SELECT notes FROM titles WHERE notes LIKE '%@%%' ESCAPE '@'
Pattern matching may be used when we have a number of expected variations for search
SELECT au_lname, au_fname FROM authors WHERE au_fname LIKE '[l,m,s]%'
Suppose we want to retrieve four letter name whose first char is capital and other are small
SELECT au_lname, au_fname FROM authors WHERE au_lname LIKE '[A-Z][a-z][a-z][a-z]'
Suppose in a case sensitive column we want to retrieve book with title
“life without fear”, but do not know that without is capital or small
SELECT title_id, title FROM titles WHERE title LIKE '%[Ww][Ii][Tt][Hh][Oo][Uu][Tt]%'
We want to retreive just those authors whose first name is 4 char long
SELECT au_fname FROM authors WHERE au_fname LIKE '____'
We can use negate by using <>, !=, ^, not
SELECT au_fname FROM authors WHERE au_fname LIKE '[^][^][^][^]'
You have a column that accepts just 6 chars while inserting data you have to be careful for signs and digits use ‘[A-z][A-z][A-z][A-z][A-z][A-z]’
Order by may be used with column names or numbers. Also we may use calculations for order criteria. Nulls will be placed at start or end of list as spcified by DBMS
SELECT au_fname+au_lname name FROM authors ORDER BY name
Distinct is used just after select key word. Only one distinct may be there per SQL statement. Will be applied to all columns in select list
Distinct performs like group by except it does not sort the data
SELECT DISTINCT [TYPE] FROM titles
Group by works same as distinct. True power comes with aggregate functions like count(). An aggregate can not be specified in group by clause. when using group with aggregate, u have to specify all non aggregate. clolumns in group by clause
SELECT [STATE], COUNT(*) FROM authors GROUP BY [STATE]
- Having clause works like where with a fundamental difference.
- Where clause defines set of data on which grouping is perfomed.
- Having clause defines which groups are going to be return to user. Having clause generally contains aggregates as part of selection criteria
Compute and compute by
Compute is used to generate summary data. It is backword compatibility. Analysis services roll up is advance to it. Following restrictions are applied.
- U can use columns in select list only.
- U must order by compute by column.
- U can use any aggregate function except count(*).
- Columns listed after compute by should be identical to those ordered in select clause
Suppose we have a table Tab1 in database DB1. And it is required to move the Tab1 to another database DB2. So it is assumed that DB2 already exists with no or some tables in it. First of all use following T-SQL command to copy table in to destination database with all data in it.
SELECT * INTO DB2..Tab1 FROM DB1..Tab1 GO
Now if you have to just copy the table then its over but if you are required to move the table then use following command to drop the table from source database.
DROP TABLE DB1.Tab1 GO
As you can see that it is done by select statement, so no affiliated objects like triggers, views etc will be copied.