第一次系统地玩QT,于是诞生了此预备式: 【QT版本4.6.0(VS2008编译版),开发平台推荐使用Qt Creator(最新1.3版),系统这里使用Windows Xp】 QT Qt Creator MySql安装: QT :不知道QT开发人员怎么想的,总是跟空格过不去,安装QT时尽量将其装在根目录下
第一次系统地玩QT,于是诞生了此预备式:
【QT版本4.6.0(VS2008编译版),开发平台推荐使用Qt Creator(最新1.3版),系统这里使用Windows Xp】
QT & Qt Creator & MySql安装:
QT:不知道QT开发人员怎么想的,总是跟空格过不去,安装QT时尽量将其装在根目录下,路径中尽量不要有中文,否则由于这问题出现诡异情况,GOOGLE都不一定好使~
Qt Creator:我的Qt Creator是在VS2008安装完成之后装的。装完Creator,它就默认使用VS编译器了(如果有问题,从VS环境变量、QT环境变量入手!)。但这也带来一个问题,就是调试器不能用GDB,要用微软的CDB(下载地址),在上面挑个最新版的下载安装。我这里Creator用的是1.3版的,对于CDB兼容性还是有问题的,会提示找不到"dbgeng.dll"。这时需要把CDB安装文件夹中的"dbghelp.dll"拷贝到Creator的Bin目录下,完成后就可以正常使用CDB调试了。
MySql:MySql装上去通常会出现万恶的1067错误,针对该错误的解决方法可谓五花八门。这里MySql建议安装完全版的(除非很了解MySql,不然就不要安装Essential版),装的时候也是尽量挑英文无空格路径装,免得万一因路径出问题折腾。MySql的配置方法:
- 把my-small.ini拷贝成my.ini
- 在其中的[client]下加上default-character-set=GBK;在[mysqld]下加上default-character-set=GBK、basedir = "D:/MySql"(MySql路径)、datadir = "D:/MySql/data"(数据库路径)、tmpdir = "D:/MySql//temp"(临时文件夹,注意双"/"转义"/t")。其中各路径根据MySql安装情况自己修改。
- 在my.ini旁边创建一个文本文件,文件名改为Create.bat。用记事本打开,粘进如下代码:
<pre class="brush:php;toolbar:false">@echo off
cd/d %~dp0
@echo Build DataBase ...
mkdir data
mkdir temp
copy /V /Y "./my.ini" "%windir%/my.ini"
./bin/mysqld.exe --defaults-file="./my.ini" --console
@echo Failure.
pause
并运行该批处理。如果最后未出现Failure输出,则创建数据库成功!创建成功后,关闭Create.bat批处理运行窗口。
- 在my.ini旁边再创建一个文本文件,文件名改为Rebuild_And_Start_Service.bat。用记事本打开,粘进如下代码:
<pre class="brush:php;toolbar:false">@echo off
cd/d %~dp0
@echo Now Reinstall MySql Service ...
./bin/mysqld.exe --remove
./bin/mysqld.exe --install MySql
@echo Start Service ...
net start MySql
@echo done.
pause
并运行该批处理。人品不错的话,应该是顺利启动服务了,碰1067的话GOOGLE去吧~
- 为了日后管理方便,需要再创建个批处理来停止MySql服务。 在my.ini旁边再创建一个文本文件,文件名改为Stop_Service.bat。用记事本打开,粘进如下代码:
<pre class="brush:php;toolbar:false">@echo off
net stop MySql
echo done.
pause
并运行该批处理。关闭服务的批处理通常都是最好使的,双击即关闭。
- 再补充一个启动MySql服务的批处理Start_Service.bat,便于在Stop_Service.bat运行后再次启动服务:
<pre class="brush:php;toolbar:false">@echo off
net start MySql
echo done.
pause
- 上面一切都搞定,MySql服务运行后,就可以运行MySql安装文件夹下Bin目录中的mysql.exe,试试MySql功能正常不。
- MySql可以启动并正常使用后,将MySql数据库驱动(点击看编译方法)拷贝到“%QTDIR%/plugins/sqldrivers”中。在MySql安装目录中找到“libmysql.dll”,并将其拷贝到“%QTDIR%/bin”下。
关于带数据库驱动的QT程序的部署:在QT程序的main函数中,使用QCoreApplication::addLibraryPath()添加库文件加载路径。
QT的中文化
<pre class="brush:php;toolbar:false"><span>int</span> main(<span>int</span> argc, <span>char</span> *argv[])
{
QApplication a(argc, argv);
<span>//设置tr以及地域。</span>
QTextCodec::setCodecForLocale(QTextCodec::codecForName("<span>GBK</span>"));
QTextCodec::setCodecForCStrings(QTextCodec::codecForName("<span>GBK</span>"));
QTextCodec::setCodecForTr(QTextCodec::codecForName("<span>GBK</span>"));
<span>//添加库加载路径。</span>
QCoreApplication::addLibraryPath(QCoreApplication::applicationDirPath() + '/' + PLUGINS_NAME);
Widget w;
w.show();
<span>return</span> a.exec();
}
注意:tr只有在类中已经继承了QObject时才可以直接使用,否则可以使用QObject::tr()。

TograntpermissionstonewMySQLusers,followthesesteps:1)AccessMySQLasauserwithsufficientprivileges,2)CreateanewuserwiththeCREATEUSERcommand,3)UsetheGRANTcommandtospecifypermissionslikeSELECT,INSERT,UPDATE,orALLPRIVILEGESonspecificdatabasesortables,and4)

ToaddusersinMySQLeffectivelyandsecurely,followthesesteps:1)UsetheCREATEUSERstatementtoaddanewuser,specifyingthehostandastrongpassword.2)GrantnecessaryprivilegesusingtheGRANTstatement,adheringtotheprincipleofleastprivilege.3)Implementsecuritymeasuresl

ToaddanewuserwithcomplexpermissionsinMySQL,followthesesteps:1)CreatetheuserwithCREATEUSER'newuser'@'localhost'IDENTIFIEDBY'password';.2)Grantreadaccesstoalltablesin'mydatabase'withGRANTSELECTONmydatabase.TO'newuser'@'localhost';.3)Grantwriteaccessto'

The string data types in MySQL include CHAR, VARCHAR, BINARY, VARBINARY, BLOB, and TEXT. The collations determine the comparison and sorting of strings. 1.CHAR is suitable for fixed-length strings, VARCHAR is suitable for variable-length strings. 2.BINARY and VARBINARY are used for binary data, and BLOB and TEXT are used for large object data. 3. Sorting rules such as utf8mb4_unicode_ci ignores upper and lower case and is suitable for user names; utf8mb4_bin is case sensitive and is suitable for fields that require precise comparison.

The best MySQLVARCHAR column length selection should be based on data analysis, consider future growth, evaluate performance impacts, and character set requirements. 1) Analyze the data to determine typical lengths; 2) Reserve future expansion space; 3) Pay attention to the impact of large lengths on performance; 4) Consider the impact of character sets on storage. Through these steps, the efficiency and scalability of the database can be optimized.

MySQLBLOBshavelimits:TINYBLOB(255bytes),BLOB(65,535bytes),MEDIUMBLOB(16,777,215bytes),andLONGBLOB(4,294,967,295bytes).TouseBLOBseffectively:1)ConsiderperformanceimpactsandstorelargeBLOBsexternally;2)Managebackupsandreplicationcarefully;3)Usepathsinst

The best tools and technologies for automating the creation of users in MySQL include: 1. MySQLWorkbench, suitable for small to medium-sized environments, easy to use but high resource consumption; 2. Ansible, suitable for multi-server environments, simple but steep learning curve; 3. Custom Python scripts, flexible but need to ensure script security; 4. Puppet and Chef, suitable for large-scale environments, complex but scalable. Scale, learning curve and integration needs should be considered when choosing.

Yes,youcansearchinsideaBLOBinMySQLusingspecifictechniques.1)ConverttheBLOBtoaUTF-8stringwithCONVERTfunctionandsearchusingLIKE.2)ForcompressedBLOBs,useUNCOMPRESSbeforeconversion.3)Considerperformanceimpactsanddataencoding.4)Forcomplexdata,externalproc


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SublimeText3 Mac version
God-level code editing software (SublimeText3)

SublimeText3 English version
Recommended: Win version, supports code prompts!

SublimeText3 Linux new version
SublimeText3 Linux latest version
