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How to delete duplicate rows from table in sql

Posted By :Ashutosh Jha     Posted Date :July 30, 2014    Points :40   Category :Sql Server 
One can achieve this like below-

SELECT min(rowid) FROM table_name B
WHERE A.key_values = B.key_values);

You can also find related Interview Question to How to delete duplicate rows from table in sql  below: 

How To Delete Description Value for a Column in Table using SQL Command?

We can Delete Description from Column using sp_dropextendedproperty System Store Procedure.
Sample Command to Delete Description from Column in a Table:

EXEC sys.sp_dropextendedproperty @name=N'MS_Description', @value=N'My Description for Column Here' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'MyTableName', @level2type=N'COLUMN',@level2name=N'ColumnName' (More...)

How many ways return rows from one table not in another table?

There are at least 5 ways to return data from one table which is not in another table. Two of these are SQL Server 2005 and greater only




4)OUTER APPLY (2005+)

5)EXCEPT (2005+)


Deleting Duplicates rows from the table?

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Difference Between Delete and Truncate

.Delete table is a logged operation, so the deletion of each row gets logged in the transaction log, which makes it slow.

. Truncate table also deletes all the rows in a table, but it won't log the deletion of each row, instead it logs the de-allocation of the data pages of the table, which makes it faster. Of course, truncate table cannot be rolled back.

. Truncate table is functionally identical to delete statement with no "where clause" both remove all rows in the table. But truncate table is faster and uses fewer system and transaction log resources than delete.

. Truncate table removes all rows from a table, but the table structure and its columns, constraints, indexes etc., remains as it is.

. In truncate table the counter used by an identity column for new rows is reset to the seed for the column.

. If you want to retain the identity counter, use delete statement instead.

. If you want to remove table definition and its data, use the drop table statement.

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What are the privileges that can be granted on a table by a user to others?

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