delete duplicate rows in sql

a. Customer No.> = B. Customer No. Group by A. Customer No., B. company name order by no;2. SQL Server 2005 constructs the sequence number column Method 1:Select rank () over (order by customer No. DESC) as No., customer No., company name from customer; Method 2:With table(Select row_number () over (order by customer No. DESC) as No., customer No., company name from customer)Select * from tableWhere no. Between 1 and 3; 3. rowid in Oracle can also

We provide two SQL statements for deleting duplicate records. One is to use idnotin as an instance, which is also a method for joint query, the second is to delete duplicate records from temporary tables. To delete duplicate reco

My most common method is The code is as follows Copy Code Delete ID duplicate data, suitable for ID is manual primary keyDelete Person as a from as a,(Select *,min (ID) from person GROUP by ID having count (1) > 1) as Bwhere a.id = b.ID Look for duplicates and get rid of the smallest one. The code is as follows Copy Code

In thousands of records, there are some same records, how can you use SQL statements, delete duplicates1, look for redundant records in the table, duplicate records are based on a single field (Peopleid) to determineSELECT * from Peoplewhere Peopleid in (select Peopleid from People GROUP by Peopleid have count (Peopleid) > 1)2,

In thousands of records, there are some same records, how can you use SQL statements, delete duplicates1, look for redundant records in the table, duplicate records are based on a single field (Peopleid) to determineSELECT * from Peoplewhere Peopleid in (select Peopleid from People GROUP by Peopleid have count (Peopleid) > 1)2,

SQL: delete duplicate data. Only one record is retained. SQL2010-09-10 16:03:33 Read82 Comment0 Font Size:LargeMediumSmallSubscription There are some identical records in thousands of records. How can I use SQL statements to delete duplicates? 1. Search for redundant

Tags: update repeat number post does not contain tle based on row containing pluralWith SQL statements, delete duplicates only keep one In thousands of records, there are some same records, how can you use SQL statements, delete duplicates1, look for redundant records in the table,

Write a SQL query to delete all duplicate e-mail entries in a table named Person , keeping unique emails based on its smallest Id. +----+------------------+| Id | Email |+----+------------------+| 1 | [Email protected] | | 2 | [email protected] | | 3 | [Email protected] |+----+------------------+id is the primary key, column for th

Label: with the SQL statement, delete duplicates only keep one in thousands of records, there are some identical records, how to use SQL statements, delete duplicates1, duplicate records in the lookup table are judged by a single field (Peopleid) .Select* frompeoplewherePeop

. Customer No. group by a. Customer No., B. company name ORDER BY no;2. SQL Server 2005 constructs the sequence number column Method 1:Select rank () OVER (order by customer No. DESC) AS No., customer No., company name FROM customer;Method 2:WITH TABLE(SELECT ROW_NUMBER () OVER (order by customer No. DESC) AS No., customer No., company name FROM customer)SELECT * FROM TABLEWHERE no. BETWEEN 1 AND 3;3. rowid in Oracle can also be seen as the default id

Tags: http data sp DIV on C EF R BSWith SQL statements, delete duplicates only keep oneIn thousands of records, there are some same records, how can you use SQL statements, delete duplicates1, look for redundant records in the table, duplicate records are based on a single f

Label:With SQL statements, delete duplicates only keep one In thousands of records, there are some same records, how can you use SQL statements, delete duplicates1, look for redundant records in the table, duplicate records are based on a single field (Peopleid) to determine

During the internship, a large amount of data was collected using the "thief" program, but many of them were repeated. Delete the duplicate data (keep one record) according to the practice requirements, and delete several data tables And put the data in a data table. Based on your own experience, let's take a few points. 1. Merge data tables There is a select int

Delete a duplicate data SQL statementMethod One Suppose there is a duplicate field of name,address that requires a unique result set for both fieldsSelect Identity (int,1,1) as Autoid, * into #tmp from TableNameSelect min (autoid) as autoid into #tmp2 from #tmp Group by name,autoidSELECT * from #tmp where autoid in (s

Duplicate records may occur in the Database due to some reasons, such as user input or data import failure. if you do not use primary keys, constraints, or other mechanisms to implement data integrity, record them in your database. now let's look at how to delete these records in SQL SERVER 2008. First, we can simulate some simple

MySQL Tutorial SQL distinct delete duplicate records How to use the DISTINCT keyword in MySQL to filter duplicate values in the result list of a SELECT statement If you want to delete duplicate data while querying the data, you