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table TableNameSELECT * Into TableName from #Tmpdrop table #TmpThis duplication occurs because the table is poorly designed and the unique index columns are added to resolve.2, this kind of repetition problem usually requires to keep the first record in the duplicate record, the operation method is as followsSuppose there is a duplicate field name,address, which requires the result set to be unique for bot
One, query a field repeat
Copy Code code as follows:
SELECT *
From User u
where U.user_name in (select U.user_name
From User u
GROUP BY U.user_name has count (*) > 1)
Two, delete the duplicate of a few fields in the table
Example: There are six records in the table. Where John and Harry recor
SQL deletes duplicate and SQL duplicate records in a table.
I have encountered the problem of Repeated Records in the table. The fastest way to directly write SQL statements to delete
Just want to write a delete duplicate statement and keep a data of SQL, online check a part of the information written in very detailed, but still here to write their own understanding, in order to follow the study. As follows:Table fields and data:SQL statements:[SQL]View PlainCopy
DELETE from`User`WHEREID notinch(SELECT* from(SELECTID from`User`GROUP byuser
For example, now there is a person table (table name: peosons)If you want to have the name, ID number, address of these three fields exactly the same records query
Copy Code code as follows:
Select p1.*
From persons p1,persons P2
where p1.idand P1.cardid = P2.cardid and P1.pname = p2.pname and p1.address = p2.address
can achieve this effect.
Several
Repeat | duplicate record
if exists (SELECT * from dbo.sysobjects WHERE id = object_id (N ' [dbo].[ P_qry] and OBJECTPROPERTY (ID, N ' isprocedure ') = 1)
drop procedure [dbo]. [P_qry]
Go
/*--Common stored procedures for querying duplicate records
You can query that the data in the table is duplicated, and here is th
records.If the table needs to delete duplicate records (one record is retained), you can delete the record as follows:Select distinct * into # TMP from tablenameDrop table tablenameSelect * into tablename from # TMPDrop table # TMPThe reason for this repetition is that the table design is not weekly. You can add a unique index column.2. Repeat problems usually r
If you like these articles, click here to subscribe to this BlogMySQL Method for querying and deleting duplicate records (1) 1. Find excess duplicate records in the Table. duplicate records are based on a single field (peopleId) s
field = @idFetch cur_rows into @id, @maxEndClose Cur_rowsSET ROWCOUNT 0Method TwoThere are two meanings of duplicate records, one is a completely duplicate record, that is, all fields are duplicated records, and the second is some key field duplicate
For example, you can query and list duplicate data twice. The code is as follows:Copy code Select * from park_room where parkNum in (Select parkNum from park_roomGroup by parkNumHaving count (parkNum)> 1) Order by parkNum field information description:Park_room -- parking space tableParkNum -- parking space number ExampleRemove duplicate
This article mainly introduces the distinct statement in MySQL to query duplicate records and related performance discussions. the point in this article is to avoid using distinct in top-level queries under certain circumstances, for more information, see MySQL Query. duplicate
How to query and delete duplicate records(1)1. Search for redundant duplicate records in the Table. duplicate records are determined based on a single field (peopleid ).Select * from pe
;1)
5, find redundant records in the table (multiple fields), not including ROWID minimum records SELECT * from Vitae a where (A.PEOPLEID,A.SEQ) in (select Peopleid,seq from V Itae GROUP BY PEOPLEID,SEQ has count (*) > 1) and rowID not in (select min (rowid) from Vitae GROUP by Peopleid,se Q has count (*) >1) (ii) For example, There is a field "name" in Table A, and the "name" value may be the sam
conditions are written.Suppose there are four tables: Customers, Orders, OrderDetail, articles, now assume that the problem with SQL is to find all the customers who have lived in the city of Gotham in the last six months and ordered a bat car. Of course, there are several ways to write this query, and the proponents of ANSI SQL may write the following statement
)5. Find redundant duplicate records (multiple fields) in the table, not including the smallest ROWID recordsSELECT * FROM Vitae awhere (A.PEOPLEID,A.SEQ) in (select Peopleid,seq from Vitae GROUP by PEOPLEID,SEQ have count (*) > 1)and rowID not in (select min (rowid) from Vitae GROUP by PEOPLEID,SEQ have Count (*) >1)First look at the table myempFind records with
need to modify the source code. So in practice, this situation can set the combo box control's RowSourceType property value to "2-alias", and then the item that needs to be displayed in the combo box control from the table query out of the tables to generate a table or cursor, Dynamically assign a value to the RowSource property of the combo box control, so that you can solve the problem that you just mentioned. But there's a small problem here. The
ObjectiveThis article mainly introduces to you about MySQL query, delete duplicate record of method, share out for everyone reference study, below to see detailed introduction:Find records for all repeating headings:?
1
selecttitle,count(*) as count from user_table group by title havingcount>1;
?
1
SELECT* FROM
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