a certification meaning

SELECT a.*, 1 deletable, ' year_on, ' month_on, Tool_status status0 from TOOL aDescription: Where the tool field has the Tool_status field.Question: 1 deleteable, ' year_on What do these new fields mean?A: There are no deleteable,year_on fields in the tool table, and these fields are required on the page, so you can use 1 deleteable in the query table, ' year_on queries out

Thoroughly understand the meaning of this keyword This keyword is a concept that I think is very difficult to understand, and it may be the reason for being too stupid. This keyword means that the appropriate handle can be generated for the object that has called its method. How do you understand this passage? Thinking in Java has an example There are two objects of the same type, called

= the "http://www.w3.org/1999/xhtml" xmlns attribute defines one or more namespaces that can be selected in the document. This property can be placed in the start tag of any element within the document. The value of this property is similar to a URL, it defines a namespace, and the browserThis namespace is used for all content within the element that contains the attribute. xmlns in 3. The head of the docum

Ask the meaning of a wordpress statement $ templates = array (); If (''! ==$ Name) $ Templates [] = "header-{$ name}. php "; $ Templates [] = 'header. php '; This program judges whether $ name is null. if not, assign $ templates [] "header-{$ name}. php" But then $ templates [] = 'header. php'; then templates is finally header. php. What is the role of the previous judgment?

Principle:Locate the specified controller through the URL address get parameter and make the corresponding method call requestHTTP//URL/index.php?m= module name c= Controller a= methodThe thinkphp framework URL can have the following four types1.http://URL/index.php?m= Module name c= Controller a= method Basic get mode2.http://URL/index.php/Module/controller/method Path mode PathInfo3.http://URL/module/cont

Meaning of the copy only option when backing up a database in sqlserver Copy backup onlyWith copy_only The database is usually changed during backup, which affects other backup and restoration methods. However, for special purposes, You must perform a backup that does not affect the overall backup and restoration process of the database. Full backupIt is g

(){...}} Class B overrides the common method methoda of Class A and the virtual method methodb of Class A. Then:A A = new B ();A. methoda (); // The methoda method of Class A will be called.A. methodb (); // The methodb method of Class B will be called. B is

Two-dimensional code generation--http://cli.im/forage QR Code, commonly used to generate two-dimensional code for mobile phone accessFont Conversion--Http://www.fontsquirrel.com/tools/webfont-generatorBlog Forum Class--Http://www.webhek.com a great God's personal front-end site, worth watchingResource Site--Http://www.webhek.com Lazy People Library, plug-in use, but most of the writing is not well, often need to manually modify the source codeLearning

When using the CSS3 property, most of these identifiers are prefixed to the previous point of the browser to be recognized. Now the latest version of the browser basically support CSS3 basically do not have to write a prefix, write the prefix is to forward compatible with the old version of the browser just.-ms-transform: //-ms on behalf of IE kernel Identification code-moz-transform: -webki

The margin tag can take one, two, three, and four parameters, each with a different meaning. margin:20px (upper, lower, left and right 20px.) ) margin:20px 40px; (upper, Lower 20px; left and right 40px.) ) margin:20px 40px 60px; (top 20px; left and right 40px; lower 60px.) ) margin:20px 40px 60px 80px; (upper 20px; right 40px; lower 60px; left 80px.) ）Using margin in CSS allows you to margin-top,margin-righ

Ask the meaning of a wordpress statement $ templates nbsp; array (); if nbsp; ( nbsp ;! Nbsp; $ name nbsp;) $ templates [] nbsp; header-{$ name }. php; $ templates [] nbsp; header. php ask the meaning of a wordpress statement $ Templates = array (); If (''! ==$ Name) $ Templates [] = "header-{$ name}. php ";

From warnings import filterwarnings, Catch_warningswith catch_warnings (): If Sys.py3kwarning:filterwarnings ("IG Nore ",". *mimetools has been removed ", deprecationwarning) import Mimetoolsimport socketserver For this piece of code, start the first sentence From warnings import filterwarnings, catch_warnings Here import catch_warning, but here really didn't read With Catch_warnings (): If sys.py3kwarning:filterwarnings ("Ignore", ". *mimetools have been removed", deprecationwarning) Import Mim

Chain settings 4 Hadoop.security.group.mapping Org.apache.hadoop.security.ShellBasedUnixGroupsMapping Class settings for a list of users within a group 5 Hadoop.security.authorization False Service-Side Certification Open 6 Hadoop.security.authentication Simple No Authentication or authentic

in China. Example: http://www.rol.cn.NET/talk/talk1.htm Its computer domain name is www.rol.cn.Net. The hypertext file (the file type is. html) is the talk1.htm under the directory/talk. This is the address of the chat room, which can enter the 1th room of the chat room. 2. The URL of the fileWhen a file is represented by a URL, the server is represented by a fi

than or equal to "ARG2", respectively. "ARG1" and "ARG2" are integers.=====================================================================Basically the same as other scripting languages. There's no big difference. But it's worth noting that. [] inside the condition to judge.1. String judgmentSTR1 = str2 When two strings have the same content, length is trueStr1! = str2 True when string str1 and str2 are not equal-N str1 True when the length of the string is greater than 0 (string non-null)-Z s

Tag: operation cannot arithmetic condition style description size Pre UnionA?b:cThis is a conditional expression, which means that if a is true, the expression value is B, and if A is false, the expression value is CThe conditional expression is specified as followsConditional statements:if (a>b) max=

Ask the meaning of a regular expression and urgently use ob_start (); Ob_end_clean (); $ Output = preg_match_all ('// I', $ post-> post_content, $ matches ); $ First_img = $ matches [1] [0]; Ob_start (); and ob_end_clean (); read the content of the article into the buffer zone. $ Output = preg_match_all ('// I', $ post-> post_content, $ matches ); This sentence indicates matching the image contained in th

down Good process-oriented. A small program can be compiled quickly. It does not need to be analyzed, modeled, or run fast. The process orientation is not good. What should I do for a large project and how to maintain tens of thousands or even hundreds of thousands of codes in the enterprise? This brings out the bug. No matter whether object-oriented or process-oriented, it is just an organizational form o

Iterative parsing is the use of the iteration protocol to list (of course, not only the list, but also the file object or dictionary, etc., where the item in list A is processed) is taken out (for x in a) the same processing in the expression x+10;The map function also takes the item out of the list for function processing, but this is not the idea of using the iterative protocol, but the map. MapReduce tho

callable implements concurrent programming of the presence return value. (Call's return value string is affected by generics)Also callable, use the future to get the return value.Paste a complete and running program code Futuretest.java Packagedemo.future;Importjava.util.ArrayList;Importjava.util.List;Importjava.util.concurrent.*; /*** Experiment with Java's future usage*/ Public classFuturetest { Public Static classTaskImplementsCallable{@Override P