group by name

This method is supported in SQL Server or oracle, but mysql does not currently support it. A similar error is reported: Youcan This method is supported in SQL Server or oracle, but mysql does not currently support it. An error similar to: You can

DBGrid displays the values of different fields in two tables. Delphi/Windows SDK/API Http://www.delphi2007.net/DelphiDB/html/delphi_20061215211111282.html Hello everyone, you have encountered the following questions for help, There are two

There are two Repeated Records. One is a completely repeated record, that is, records with all fields being repeated, and the other is records with duplicate key fields, such as duplicate name fields, other fields are not necessarily repeated or can

Today, my friend asked a particularly tangled question: In a table in the database, the table duplicates a field in the table and sorts the remaining data according to another field, Create a table as follows: Create table TEST_DISTINCT (ID integer

With rollup and MySQLWITHROLLUP in MySQL MySQL's extended SQL has a very interesting application WITH ROLLUP. The same statistics (SUM, AVG, COUNT…) are performed based on the grouping statistics ...), Similar to the statistical functions in Oracle,

For example, there is a personnel table (table name: peosons) Select P1. * from persons P1, persons P2 where p1.id <> p2.id and p1.cardid = p2.cardid and p1.pname = p2.pname and p1.address = p2.address The above results can be achieved. Several

Webjxcom prompt: for example, if you want to query records with the same name, ID card number, and address in the current table (table name: peosons), select P1. * from persons P1, persons P2 where p1.idp2. ID and p1.cardid = p2.cardid and p1.pname =

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 peopleWhere peopleid in (select peopleid from people group by

SQL statement for querying and deleting duplicate records1. Search for redundant duplicate records in the Table. duplicate records are determined based on a single field (peopleid ).Select * from peopleWhere peopleid in (select peopleid from people

SQL statement for querying and deleting duplicate records1. Search for redundant duplicate records in the Table. duplicate records are determined based on a single field (Id ).Select * from table where Id in (select Id from Table group by Id having

With rollup in MySQL MySQL's extended SQL has a very interesting application WITH ROLLUP. The same statistics (SUM, AVG, COUNT…) are performed based on the grouping statistics ...), Similar to the statistical functions in Oracle, Oracle's

This article introduces how to use havinggroupby and various selectin joint queries to filter the SQL language names of Repeated Records in different ways. This article introduces how to use having group by and various select in joint queries to

How to find out the duplicate records of field values in the same table(2013-03-25 11:28:51)reproduced For example, there is now a table (table name: peosons) If you want to name, social Security number, address the three fields exactly the same

No details none-data of the row where the maximum (small) value is located is grouped by a certain field * data is as follows: namevalmemoa2a2 (second value of) a1a1 -- the first value of a a3a3: The third value of a b1b1 -- the first value of B b3b3

When MySQL is used to query multiple non-repeated record values using distinct, it is sometimes necessary to query records with no repeated fields, although mysql provides the keyword distinct to filter out redundant duplicate records and retain

WITHROLLUP in MySQL MySQL's extended SQL has a very interesting application WITH ROLLUP. The same statistics (SUM, AVG, COUNT…) are performed based on the grouping statistics ...), Similar to the statistical functions in Oracle, Oracle's statistical

How to Use distinct to query multiple unique record values in mysql How to Use distinct to query multiple unique record values in mysql When using mysql, you sometimes need to query records with unique fields. Although mysql provides the keyword

We often encounter the need to delete repeated records in a data table. Below I will summarize several methods that can delete Repeated Records and help to improve efficiency. For more information, see. We often encounter the need to delete repeated

When using mysql, you sometimes need to query records with unique fields. Although mysql provides the keyword distinct to filter out redundant duplicate records, only one record is retained, but it is often used to return the number of records that

1. query a field already exists.Copy codeThe Code is as follows:Select *From User uWhere u. user_name in (select u. user_nameFrom User uGroup by u. user_name having count (*)> 1)2. Delete repeated fields in the table For example, a table contains