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I have a table in sql server with two fields named 'start_time' and 'stop_time'. both fields have datatype set as 'datetime'. now I want to subtract the 'start_time' from 'stop_time'? I have tried datediff() fuction,but no use. I want the correct outpput of date as well as time . Need help as early as possible.
satheyaraaj
- Jul 9th, 2011
Select DATEDIFF(MI,FromTime,ToTime) From ShiftMaster -- between no of minutesselect DATEDIFF(HH,FromTime,ToTime) From ShiftMaster -- between no of Hours
swathi660
- Jan 15th, 2009
Select starttime,stoptime,datediff(day,starttime,stoptime) as newtime from date.try this...........
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Which is the best option used to move database from one server to another serve on same network?a) Import - Exportb)Backup-Restorec)Detach-AttachWhy?
kirandba
- Apr 1st, 2010
Backup and Restore works well and its also faster when compare to copying data and log file. Impoert/Export works well if your dealing with very small databases. If we have few million rows its takes minutes to copy when compared to seconds using backup and restore.
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Define Unique Key in SQL Server
How to define unique key in table? Is it possible to define one primary key and one unique key in a single table?
asifeqbal
- Mar 19th, 2015
UNIQUE key constraint enforce uniqueness of the column on which they are defined. It allows the column to have distinct & one NULL values. We can make one or more columns unique in a table by defining...
erik
- Jul 21st, 2012
SQL UNIQUE key... The UNIQUE constraint uniquely identifies each record in a database table. The UNIQUE and PRIMARY KEY constraints both provide a guarantee for uniqueness for a column or set of col...
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What is a "trigger"?
neel_desai
- Oct 11th, 2008
A trigger is a special kind of stored procedure that automatically executes when an event occurs in the database server. There are three types of triggers: 1. DML trigger &nbs...
sreyas kvm
- Feb 3rd, 2008
Trigger is a self executing event in sql server where a relevent action is occured.triggers are useful in master-child relation ship in a table.Trigger can be created as,create trigger triggername on tablename for insert,update,delete as "necessory action"
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Difference between "ORACLE" and "MICROSOFT ACCESS" databases?
mragu1986
- Mar 16th, 2009
Oracle is more secure than MS Access.Oracle stores unlimited data while MS
Access is not.Sequence creation is not possible in MS Access.Oracle is scalable but not
MS Access.Shoby
- May 9th, 2006
Oracle is ORDBMS (Object Oriented Relational DataBase) while Access is RDBMS(Relational DataBase) only.
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What is the query used to display all tables names in SQL Server (Query analyzer)?
srikanth tirunagari
- May 25th, 2007
select TABLE_NAME from INFORMATION_SCHEMA.TABLES where TABLE_TYPE = 'BASE TABLE'
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What is the difference between Inner join and full outer join in terms of the Number of rows returned?
zeekhan
- Aug 12th, 2009
Inner Join returns matching records onlyA full outer join returns all rows in both the left and right tables
sa_dub
- May 4th, 2009
Inner Join is used to join two coloumns of the same table which have some same attributes but Outer Join used for join two coloumns of different tables which have unmached attributes.
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What are data objects?
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What is the difference between Varchar and Varchar2?
neel_desai
- Oct 11th, 2008
There is no VARCHAR2 in SQL server.SQL Server VARCHAR = oracle VARCHAR2In SQL Server, maximum size of VARCHAR is 8000. So VARCHAR(MAX) is same as VARCHAR(8000). Also if we write VARCHAR(10000), will g...
Deepak Bhandari
- Mar 30th, 2007
varchar and varchar2: both are datatype for storing character or string type, but there are little bit difference in both, let us with following exemple if we declare a variable name as varchar(100)...
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What are the advantages of views ?
asifeqbal
- Mar 19th, 2015
1. We can restrict the users access to the stored data by using Views. User can be given permission to access database through views that contain the specific data the user is authorized to see. 2. A...
Techiee
- Jun 12th, 2013
1. Hiding Unwanted(users do not have right to see those columns e.g login, password column in table) columns from the user.
2. Reduce the complexity of tables from using joins etc. in your query. -
How to find out the no of connections in SQL server?
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How do you optimize stored procedures ?
anjan_maity
- Aug 7th, 2008
There is no hard and fast rule. It depends on you SQL statements.There some usefull guideline.Turn on Execution plan.Avoid cursorUse Cluster index (try to keep it small).If possible use 'If Exit'Try to avoid Rebuild option.
subhashsubramanyam
- Apr 17th, 2008
Optimizing Stored Procedure involves1) Identify long runnning queries and rectify issues associated with it2) Identify whether they are resource intensive (Eg: I/O intensive ? Replace Cursor...
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Transaction Isolation Level
What is a transaction isolation level and What is the advantage of it? What are different options that we set for a transaction isolation level?
Transaction isolation levels are used when we go for transactions in stored procedures used in Transact SQL.kirangiet
- Aug 17th, 2010
Isolation levels in SQL Server 2008Read UncommittedRead Committed Snapshot*Read CommittedRepeatable ReadSnapshot*Serializable* The two new Isolation levels are based on Optimistic Concurrency Model.Note: Optimistic concurrency uses row versioning instead of row locking.
myelton
- Jul 8th, 2008
You need to add Snapshot to this answer. From BOL:Specifies that data read by any statement in a transaction will be the transactionally consistent version of the data that existed at the start ...
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Subqueries vs Joins in SQL
What is the difference between Subqueries and Joins? Which is better and Why? Give an example of each.
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After trigger
Is there any reason for which we cannot use After trigger with a view?
psingla
- Mar 16th, 2010
A after trigger gets fired whenever there is any insert/update/delete happens in the table on which the trigger is defined.But the view is just a definition rather than an actual table so insert/updat...
pprasad_ktda
- Sep 4th, 2009
In a view if composite primary key is present than "After Trigger" cannot be defined.
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SQL Server Insert and Delete
1. how to insert five rows in a table using single query(in ms-sql or oracle)2.how to delete duplicate values in a table. for example, the table containing five duplicate values(like name rani). i would like to delete all four rows in a table. but not the one row.
psingla
- Mar 19th, 2010
As suggested by krishna create table test_a(a int)insert into test_a values(1)insert into test_a values(1)insert into test_a values(3)insert into test_a values(4)insert into test_a values(5)inser...
clickfreehit
- Apr 11th, 2009
Inset data:insert into targettableselect top 5 * from sourcetabledelete data:1. select distinct * into targettable from sourcetable2. delete from sourcetable3. insert into sourcetable ??? select * from targettable
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Self Join
Explain Self Join with the help of an example?
Chaitali
- Sep 29th, 2015
Self join - Joining table itself called "Self join". In Self join we need to use alias for the same table.
Example -
SELECT E.EmpID, E.Name, M.Name As Manager Name
FROM Employee E SELF JOIN Employee M
WHERE E.MgrID = M.EmpID
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What is normolization in sql server ?
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Editorial / Best Answer
Answered by: Steven
- Oct 4th, 2011
Normalizatiopn is the process of splitting tables up to reduce record redundancy. For instance if you have a table of addresses you may want to create a table of cities and link the addresses to the cities table in a foreign key. Since the city names would be identical on several records this would save a lot of space. In some cases if tables are not normalized the amount of space they would take up would be so large that it would not be possible to record the data. The amount of normalization that you choose would depend upon how often field data is repeated throughout the table.
Jatin Girdhar, Gurgaon
- Oct 12th, 2015
SQL Normalization is a systematic approach of de-composing tables to: 1. To eliminate redundant (useless) data 2. To store the data logically Benefits: 1. Removes Data redundancy 2. Improves perform...
rayudu
- Oct 11th, 2011
Normalizatilon is the process of organizing the table to minimize the redundency
SQL Server Interview Questions
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