Copy CodeThe code is as follows:
/**
* @Filename:p age.sql.class.php
* @CreatTime: 2009-01-06
* @Descrition: This class handles classes for SQL statements.
* @UpdateTime-1: null
* @Version: jswweb1.0.0
* @Author: Fkedwgwy
* @Dome:
$sql//sql Statements
$allcount//Total Record Count
$pagesize//page shows the number of record bars
$page//Current page
$SQLC = new Sqlpage ($sql, $allcount, $pagesize, $page);
$sql = $SQLC->getsql ();
The optimized statement:
SELECT * FROM (select top of LSH,ZTM,DYZRS
As we all know, Mysql paging requires the use of Limit for paging. When the data size is small, the Limit performance can be imagined. For example: {code...} the preceding SQL statement has no performance problems. However, if the offset is too low, a performance bottleneck may occur. For example, {code... as we all know, Mysql uses Limit for paging. When the data volume/Page Shard is small, the Limit performance can be imagined. For example:
SELECT pid,author,hash,dateline FROM posts WHERE pid
beginning of the program, in the following infection function section, you can use it to delete the main program body of the software. Pigs can think of problems, do not need me to say again. Because my net name is also called "pig", these must rob in the anti-virus software before running up to achieve the goal.
(2). The virus should use the deformation function as much as possible, use the new encryption algorithm, of course, the script encryption algorithm is very simple, at this point new h
greater than 1 InStr InStr (string1,string2 [, compare]) Returns the position of the first occurrence of the string1 string in the string2 string Split Split (String1,delimiter[,count[,start]) splits the string into a one-dimensional array based on delimiter. Where delimiter is used to identify substring bounds. If omitted, a space ("") is used as the delimiter. Count returns the number of substrings,-1 indicates that all substrings are returned. Start performs a text comparison for 1, or bin
-SQL Outer Join sometimes produces ambiguity, it is recommended to use the SQL-92 syntax.
Use left Outer Join
Assume that the authors table and the publishers table are joined in the city column. The results only show the author of the publisher's city (Abraham Bennet and Cheryl Carson in this example ).
To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 to connect left out. The following are the query results of the left Outer Joi
As we all know, MySQL paging is to use limit for paging, the amount of data/number of pages small when the limit performance is conceivable. Such as:
SELECT pid,author,hash,dateline FROM posts WHERE pid='123456' ORDER BY pid ASC LIMIT 100,100;
There is no problem with the SQL statement performance described above.
However, performance bottlenecks can occur if the offset is too cheap. Such as:
SELECT pid,author,hash,dateline FROM posts WHERE pid='1234
After SQL optimization, the query speed can be greatly improved.
The code is as follows:
/*** @ Filename: page. SQL. class. php* @ CreatTime: 2009-01-06* @ Descrition: This class is an SQL statement processing class.* @ UpdateTime-1: null* @ Version: jswweb1.0.0* @ Author: fkedwgwy* @ Dome:$ SQL // SQL statement$ Allcount // total number of records$ Pagesize // number of records displayed on the page$ Page // current page$ Sqlc = new sqlpage ($ SQL, $ allcount, $ pagesize, $ page );$ SQL = $
authors table and the publishers table are joined in the city column. The result is only displayed in
Author of the publisher's City (in this example, Abraham Bennet and Cheryl Carson)
).
To include all the authors in the results, regardless of whether the publisher lives in the same city, use SQL-
92 left outer join. The following are the query results of the left outer join of Transact-SQL:
USE pubs
SELECT a. au_fname, a. au_lname, p. pub_name
FROM authors a left outer join publishers p
, course = 'mat', score = mathematics from tb
Union all
Select name, course = 'physical ', score = physical from tb
) T
Order by name, case course when 'China' then 1 when' math 'then 2 when' then 3 end
-- SQL server 2000 dynamic SQL.
-- Call the dynamic ecosystem of the system table.
Declare @ SQL varchar (8000)
Select @ SQL = isnull (@ SQL + 'Union all', '') + 'select Name, [course] = '+ quotename (Name, ''') + ', [score] = '+ quotename (Name) + 'from tb'
From syscolumns
Where name! = N'name'
to use the SQL-92 syntax.
Use left Outer Join
Assume that the authors table and the publishers table are joined in the city column. The results only show the author of the publisher's city (Abraham Bennet and Cheryl Carson in this example ).
To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 to connect left out. The following are the query results of the left Outer Join of transact-SQL:
Use pubs
Select a. au_fname, A. au_ln
the city column. The result is only displayed in
Author of the publisher's city (in this example, Abraham Bennet and Cheryl Carson)
).
To include all the authors in the results, regardless of whether the publisher lives in the same city, use SQL-
92 left Outer Join. The following are the query results of the left Outer Join of transact-SQL:
Use pubsSelect a. au_fname, A. au_lname, P. pub_nameFrom authors a left Outer Join publishers POn a. City = P. CityOrder by P. pub_name
The function is as follows:
Function Dip (STR: string): string;VaRM, str1: string;ASC, asc1: byte;I: integer;BeginM: = 'asdfdghjvvvacw ';For I: = 1 to length (STR) DoBeginASC: = ord (STR [I]);ASC: = ASC and $ F;Asc1: = ord (M [I]);Asc1: = asc1 and $ F;Asc1: = asc xor asc1;ASC
title, birthdate as birthday from Employees, sqlConnection1);Initializes a SqlDataAdapter instance with a defined database connectionDataSet1 = new DataSet ();SqlDataAdapter1.Fill (DataSet1, "employee");Populating local dataset Datasets with SqlDataAdapter instancesDataView dataView1 = dataset1.tables ["Employee"]. DefaultView;Switch (sortstring){Case "Serial number":if (blid){Dataview1.sort = "Serial number DESC";Blid = false;}Else{Dataview1.sort = "Ordinal
bytes =-1 Then ' Get all!
GetBytes = Objtextstream.read (lngsize) ' ReadAll
Else
GetBytes = Objtextstream.read (bytes)
End If
Objtextstream.close
Set objTextStream = Nothing
Set objFSO = Nothing
End Function
'':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
''::: :::
'::: Functions to convert two bytes to a numeric value (long)::
'::: (both Little-endian and Big-endian):::
''::: :::
'':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
function Lngconvert (st
bytes =-1 Then ' Get all!
GetBytes = Objtextstream.read (lngsize) ' ReadAll
Else
GetBytes = Objtextstream.read (bytes)
End If
Objtextstream.close
Set objTextStream = Nothing
Set objFSO = Nothing
End Function
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
'::: :::
':: Functions to convert two bytes to a numeric value (long)::
'::: (both Little-endian and Big-endian):::
'::: :::
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
function Lngconvert (strtem
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