how to remove duplicate rows in sql

U.userid=ur. User_ID left joins Base_roleinfor R on R.role_id=ur. role_id) t where t.userid=t1. USERID for XML Path (")) as RoleName from (select R.role_name,u.userid,u.username,u.truename from base_userinfor u left Joi n base_userrole ur on u.userid=ur. User_ID left joins Base_roleinfor R on R.role_id=ur. role_id) T1 GROUP by Userid,truename,usernameLook at the results of the query, not what we want.It is important to pay attention to the following statements in the group by, although we writ

1. Find all duplicate records The code is as follows Copy Code SELECT * FROM table Where repeat field in (Select repeating field from table Group by repeating field having Count (*) >1) 2. Filter duplicate records (show only one) The code is as follows Copy Code SELECT * from Hzt Where ID in (select Max (ID) from Hzt Group by Title)

field) >1) 3. It's very easy to do a delete update on duplicate records. For example, keep only one of the minimum IDsDelete data table where ID in (the Select Max (ID) from packet Group by repeating record field has count (heavy Complex record field) >1)Update Operation No, it's the same. 4.group by field having count and distinct difference DISTCT query shows that all field values are the same, one record For exampleID Name Sex43 111 144 111 145 11

This article will introduce to you in detail the summary of SQL statement methods for deleting duplicate records in SQLServer. In general, we will delete the records in two cases, one is a completely repeated record, where all fields are repeated, and the other is a record with duplicate key fields. other fields are not repeated or repeated, but can be ignored. T

Project requirements: Multiple rows of data in a table are displayed in a single field, as follows:For example, there are field id,name in Table A,There are field id,pid,des in table B,Table A, the data in table B are as follows:ID NAME1 sheets of three2 John DoeID PID DES11 languages21 Mathematics31 Foreign languages42 History52 geographyFinally I want to show the effect as:ID NAME KC1 three languages, mathematics, foreign languages2 Li four History,

ROWID minimumDelete 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)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

Tags: server greater than from BLE tab style not row divSQL SERVER queries data between rows 20th through 301. Query the first 20 rows of the ID, after the query to remove 20 records of the first 10 recordsSelect Top * from Tbbank WHERE bankid not in (select Top BankID from Tbbank ORDER by BankID ASC) 2. Query the first 20 ro