Most of the lossless compression plans do 2 things in the sequence: first step operates statistical model for an input data, and second step makes use of the model to map the input data to sequences in a way that data can produce the shorter output than the "improbable" data. There are 2 main methods of constructing the statistical models: in the static model, data is been analyzed and model is constructed, this model is then stored with compressed data
You can find an other sql tutorial titled How to delete duplicate records or rows among identical rows in a table where no primary key exists among Kodyaz SQL articles. ORDER BY ...) to Delete Duplicate Rows in SQL Table If you have duplicate rows in your MS SQL Server database tables, you may want to delete duplicate records
Remove Duplicate Rows from a Table in SQL Server - CodeProject
Easiest way to delete more than one duplicate row from a table in SQL Server Introduction Most of the times, we use primary key or unique key for preventing insertion of duplicate rows in SQL Server. Is it too complicated? History 16th February, 2011: Initial post License This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL) Share email twitter facebook linkedin reddit google+ About the Author Sadeque Sharif Software Developer Meridian Group Bangladesh I am: Manager (IT) at Meridian Group
select * from mytable union select * from mytable, thsi query returns the exact records, and i guess we can use this data to build a new table or replacing the previous one. I need to get rid of the duplications, meaning that when names are shown more than once for a given month and year, I only want one of the duplicated intervention records to show up
We extensively use GROUP BY and we all know problem with GROUP BY (We should have all selected column from select clause in group by clause, other wise we cannot use group by). The problem is: the system by mistake inserted duplicate data in R2-R5 (R1 is PK assuem autonumber) and in one of these duplicates R6 and R7 are also filled
sql server - How to remove a column from an existing table? - Stack Overflow
You can do this by querying system tables or using third party tools such as ApexSQL Search (free) or Red Gate Dependency tracker (premium but more features). Linked 234 How can I list all foreign keys referencing a given table in SQL Server? 11 Deleting columns in MS SQL Server 2005 0 How to remove multiple columns that have only one value across all rows in SQL Server 2008 R2 Related 577 How can I remove duplicate rows? 1173 Add a column, with a default value, to an existing table in SQL Server 806 How to check if column exists in SQL Server table 460 Check if table exists in SQL Server 579 Table Naming Dilemma: Singular vs
How to delete duplicate records using SQL
Delete duplicate records Delete Duplicate Records using SQL By duplicate record I mean that every field in one record is identical to every field in a different record, i.e. To check that you have duplicate records in your table do the following: select count(*) from MyTable and select distinct * from MyTable unfortunately SQL does not permit a select count(distinct)
Result set after the usage of ranking function will look as below with all ranks defined 1 for unique values and all duplicates with values greater than 1
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