group by name

Open mysql:mysql-hlocalhost-uroot-p PasswordNext is the high energy, sometimes because of the MySQL version of the problem, the problem of the field, the problem of the space is often caused by errors, so some of the following code in your machine

One or more rows into a column (and separated by ",")Table Name: ATable data:Desired Query Results:Query statement:Select Name, value = (STUFF (select ', ' + value from A WHERE name = Test.name

Reference article:Http://www.williamsang.com/archives/1508.htmlScenario BriefThe school records the results, each person's choice course is different, and later will add the course, so do not need to take all the courses as a column. Database grade

This article lists 3 ways to delete duplicate records, namely ROWID, group by and distinct, which can be consulted by small partners.For example, there is now a person table (table name: peosons)If you want to name, ID, address, the three fields

1, the query table duplicate data. SELECT * from Peoplewhere Peopleid in (select Peopleid from People GROUP by Peopleid have count (Peopleid) > 1)2, delete redundant records in the table, duplicate records are based on a single field (Peopleid) to

Original: http://www.cnblogs.com/sammon/archive/2012/05/10/2494362.htmlTest tables and test dataCREATE TABLE Testtitle (Name VARCHAR (10),Titlevarchar (10));INSERT into Testtitle VALUES (' Zhang San ', ' Programmer ');INSERT into Testtitle VALUES ('

MySQL Group takes the first few records of each group (rank) with group by and order byHttp://www.jb51.net/article/31590.htm--group The data of the row with the maximum (small) value by a fieldThe code is as follows:--Create the table and insert the

Turn from Hibiscus bloghttp://blog.sina.com.cn/liurongxiu1211 SQL to remove duplicate statements(2012-06-15 15:00:01)SQL single table/multi-table query removes duplicate recordsSingle table DistinctMulti-table GROUP byGroup by must be placed before

with ROLLUP in MySQLThere is a very interesting application with ROLLUP in MySQL's extended SQL, which is based on the statistical data of the group and then the same statistic (Sum,avg,count ... ), very similar to the functionality of statistical

1, the query table duplicate data. SELECT * from Peoplewhere Peopleid in (select Peopleid from People GROUP by Peopleid have count (Peopleid) > 1)2, delete redundant records in the table, duplicate records are based on a single field (Peopleid) to

1, 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)Example two: SELECT *

MySQL Group takes the first few records of each group (rank) with group by and order byHttp://www.jb51.net/article/31590.htm--group The data of the row with the maximum (small) value by a fieldThe code is as follows:/**/--Create the table and insert

The code is as follows Copy Code Select A.*From temp a INNER join (select Name,sex to Temp GROUP by Name,sex has count (*) >1) bOn a.name = b.name and a.sex = B.sex To see a delete duplicate record instance User table

SQL Duplicate record query 1, look for redundant records in the table, duplicate records are based on a single field (Peopleid) to judge SELECT * from people where Peopleid to (select Peopleid from People GROUP by Peopleid have count

SQL SELECT DISTINCT Statement Grammar: SELECT DISTINCT column name from table name using DISTINCT keyword If you want to select all the values from the company column, we need to use the SELECT statement: SELECT Company from Orders To select

SQL statements for querying and deleting duplicate records1, look for redundant records in the table, duplicate records are based on a single field (ID) to judgeSELECT * FROM table where ID in (select Id from table GROUP by ID have count (Id) > 1)

For example, table T:ID Name1 AA2 BB3 cc4 AA5 AA6 cc How to become (keep the largest ID or the smallest ID):ID Name1 AA2 BB3 cc 1. Using the DISTINCT keyword, export no duplicate data to a temporary table, delete the original table, and then import

What is the difference between where and having?Where is a filter before group by, and having a filter for statistics after group by, the general having is used together with group by, combined with aggregate functions, filtered after

SQL statement for querying and deleting duplicate records 1, 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

The data type in 1.java and the corresponding relationship in SQLite Boolean 对应 INTEGER(SQLite 并没有单独的布尔存储类型，而是将布尔值存储为整数 0 (false) 和 1 (true)。) Byte 对应 INTEGER Short 对应 INTEGER Integer 对应 INTEGER Long 对应 INTEGER Float 对应 REAL