mysql query order by

In a large number of programming languages, code is processed in coded order, but in the SQL language, the first processed clause is the FROM clause, although the SELECT statement appears first, but is almost always finally processed. Each step produces a virtual table that is used as input to the next step. These virtual tables are not available to the caller (client application or external query). Only t

1,themes\default\user_transaction.dwtFound it:if$action eq order_detail}--Join in the following line:style>. Result-box{Background-color:#fff;Overflow:Hidden;font-family:Tahoma,arial,sans-serif;font-size:12px;Border:1px solid #b9d0f0;Line-height:24px}. Result-box Table{width:100%;Border-collapse:collapse;border-spacing:0}. Result-box Table TD{Height:30px;Color:#333;Border-bottom:1px solid #e3e3e3}. result-box table. TR1 TD{Color:#ff6c00}. result-box table. TD1{width:130px;padding:0 10px;Line-hei

650) This. width = 650; "src =" http://s3.51cto.com/wyfs02/M01/49/ AE /wKiom1QY_xWzpoOUAABKLvDZBOE284.jpg "Title =" qq20140917112358.jpg "alt =" wkiom1qy_xwzpoouaabklvdzboe284.jpg "/> should be used Instead of using the # symbol The difference between the two is that $650) This. width = 650; "src =" http://s3.51cto.com/wyfs02/M02/49/ AE /wKiom1QY_2LxAzPoAABM0fnAatA149.jpg "Title =" qq20140917112524.jpg "alt =" wkiom1qy_2lxazpoaabm0fnaata149.jpg "/> is directly put into the SQL to take, # Sym

Original post address:http://community.csdn.net/Expert/FAQ/FAQ_Index.asp?id=207897 Environment: SQL Server2000 +SP4 Problem:Select DateDiff (Day, ' 20040910 ', ' 20040920 ')--this sentence can be executed --and the following sentence cannot be executed (sometimes it can be executed)--sub_para is varchar (8) and the error message is: A syntax error occurred while converting from string to DateTime.SELECT * FROM T_subwhere item_local_code= ' 03004 'and DateDiff (Day,sub_para,getdate ()) =29and (su

Decode functionOracle is unique and powerful. Equivalent if else ifIF Condition = value 1 ThenRETURN (translation value 1)elsif condition = value 2 ThenRETURN (translation value 2)...elsif condition = value N ThenRETURN (translated value n)ELSERETURN (default value)END IFExample:ORDER by DECODE (A.status, ' excellent ', 1, ' good ', 2, ' mildly polluted ', 3, ' moderately polluted ', 4,' Heavy pollution ', 5, ' serious pollution ', 6Data returned in the specified orderFrom for notes (Wiz)The SQL

PHP + MySQL calculates the number of records for each table in the database and sorts the records in descending order. PHP + MySQL calculates the number of records for each table in the database and sorts the records in descending order, mysql record count this article descr

identify alternative data columns used for indexing and how to create an index best: Index data columns used for searching, sorting, and grouping are not only used for output display. In other words, the best alternative data columns for indexing are those that appear in the WHERE clause, join clause, order by, or group by clause. The data column in the output data column list that appears only after the SELECT keyword is not a good alternative colum

Example of a SOAP request for the sf bsp order number query interface Some interfaces sometimes use SOAP requests, such as the interfaces of sf bsp. I tried different methods of POST requests, either completely failing to request anything or receiving garbled characters, all ended in failure. The core code of the SOAP request for the SF interface is as follows: The Code is as follows:

Tags: BSP is left and right _id timestamp execute document AMP SQLAverage SQL query Order review durationWriting a SQL today, the requirement is to calculate the duration of each node in the execution state of an orderFor example, in the order, status 0 is the start of the order, status 3 is already audited, then need

SQL Server: Copy Code code as follows: Select Top N * out TABLE ORDER by NewID () View Plaincopy to Clipboardprint? Select Top N * out TABLE ORDER by NewID () Select Top N * out TABLE ORDER by NewID () The NewID () function creates a unique value for the uniqueidentifier type. The above statement implementation effect is to randomly r

functions to be grouped Like usage in grouping The LIKE operator is used to search for a specified pattern in a column in a WHERE clause. SELECT * FROM student where Sno like ' 1% ' Like followed by 1% description is the first character must be the value you write can be followed by other content, as long as the 1xxxxx in accordance with the form of the same; Like followed by the%1 description is the last character must be the value you write can be followed by other content, as long as it conf

: select count(*) from employee; Used with group select d_id,count(*) from employee group by d_id; The preceding statements are grouped before statistics. 2) sum () functionThe sum () function is the sum function.Instance: select num,sum(score) from grade where num= 1001;select num,sum(score) from grade group by num; Sum () can only calculate numeric fields.3) avg () functionAvg () is an average function.Instance: select avg(age) from employee;select course,avg(score) from group by course; 4) ma

MySQL query cache settings improve MySQL query performance and cache mysql First, let's take a look at the MSYQL logical framework: The image comes from high-performance mysql If QueryCache is used, the server will retrieve

/lib/mysql/suse11b-slow.log/usr/sbin/mysqld, Version: 5.5.39-log (MySQL Community Server (GPL )). started with: Tcp port: 3306 Unix socket:/var/lib/mysql. sockTime Id Command Argument # Time: 141004 22:05:48 # User @ Host: root [root] @ localhost [] # Query_time: 4.396858 Lock_time: 0.000140 Rows_sent: 0 Rows_examined: 53056use tempdb; SET timestamp = 1412431548;

In some cases, MySQL can use an index to satisfy the order by clause without additional sorting. The where condition and order by condition use the same index, and the order by order is the same as the index order, and the

First look at the MSYQL logical framework: Images from high-performance MySQL If Querycache is used, when the query receives one and the same query, the server retrieves the results from the query cache instead of parsing and executing the same query again. This can gre