最近用mysql + asp.net来写网站,既然mysql已经支持存储过程了,那么像分页这么常用的东西,当然要用存储过程啦
不过在网上找了一些,发现都有一个特点――就是不能传出总记录数,干脆自己研究吧。终于,算是搞出来了,效率可能不是很好,但是我也觉得不错了。贴代码吧直接:也算是对自己学习mysql的一个记录。
CREATE PROCEDURE p_pageList
(
m_pageNo int ,
m_perPageCnt int ,
m_column varchar(1000) ,
m_table varchar(1000) ,
m_condition varchar(1000),
m_orderBy varchar(200) ,
out m_totalPageCnt int
)
BEGIN
SET @pageCnt = 1; -- 总记录数
SET @limitStart = (m_pageNo - 1)*m_perPageCnt;
SET @limitEnd = m_perPageCnt;
SET @sqlCnt = CONCAT('select count(1) into @pageCnt from ',m_table); -- 这条语句很关键,用来得到总数值
SET @sql = CONCAT('select ',m_column,' from ',m_table);
IF m_condition IS NOT NULL AND m_condition '' THEN
SET @sql = CONCAT(@sql,' where ',m_condition);
SET @sqlCnt = CONCAT(@sqlCnt,' where ',m_condition);
END IF;
IF m_orderBy IS NOT NULL AND m_orderBy '' THEN
SET @sql = CONCAT(@sql,' order by ',m_orderBy);
END IF;
SET @sql = CONCAT(@sql, ' limit ', @limitStart, ',', @limitEnd);
PREPARE s_cnt from @sqlCnt;
EXECUTE s_cnt;
DEALLOCATE PREPARE s_cnt;
SET m_totalPageCnt = @pageCnt;
PREPARE record from @sql;
EXECUTE record;
DEALLOCATE PREPARE record;
END

MySQL'sBLOBissuitableforstoringbinarydatawithinarelationaldatabase,whileNoSQLoptionslikeMongoDB,Redis,andCassandraofferflexible,scalablesolutionsforunstructureddata.BLOBissimplerbutcanslowdownperformancewithlargedata;NoSQLprovidesbetterscalabilityand

ToaddauserinMySQL,use:CREATEUSER'username'@'host'IDENTIFIEDBY'password';Here'showtodoitsecurely:1)Choosethehostcarefullytocontrolaccess.2)SetresourcelimitswithoptionslikeMAX_QUERIES_PER_HOUR.3)Usestrong,uniquepasswords.4)EnforceSSL/TLSconnectionswith

ToavoidcommonmistakeswithstringdatatypesinMySQL,understandstringtypenuances,choosetherighttype,andmanageencodingandcollationsettingseffectively.1)UseCHARforfixed-lengthstrings,VARCHARforvariable-length,andTEXT/BLOBforlargerdata.2)Setcorrectcharacters

MySQloffersechar, Varchar, text, Anddenumforstringdata.usecharforfixed-Lengthstrings, VarcharerForvariable-Length, text forlarger text, AndenumforenforcingdataAntegritywithaetofvalues.

Optimizing MySQLBLOB requests can be done through the following strategies: 1. Reduce the frequency of BLOB query, use independent requests or delay loading; 2. Select the appropriate BLOB type (such as TINYBLOB); 3. Separate the BLOB data into separate tables; 4. Compress the BLOB data at the application layer; 5. Index the BLOB metadata. These methods can effectively improve performance by combining monitoring, caching and data sharding in actual applications.

Mastering the method of adding MySQL users is crucial for database administrators and developers because it ensures the security and access control of the database. 1) Create a new user using the CREATEUSER command, 2) Assign permissions through the GRANT command, 3) Use FLUSHPRIVILEGES to ensure permissions take effect, 4) Regularly audit and clean user accounts to maintain performance and security.

ChooseCHARforfixed-lengthdata,VARCHARforvariable-lengthdata,andTEXTforlargetextfields.1)CHARisefficientforconsistent-lengthdatalikecodes.2)VARCHARsuitsvariable-lengthdatalikenames,balancingflexibilityandperformance.3)TEXTisidealforlargetextslikeartic

Best practices for handling string data types and indexes in MySQL include: 1) Selecting the appropriate string type, such as CHAR for fixed length, VARCHAR for variable length, and TEXT for large text; 2) Be cautious in indexing, avoid over-indexing, and create indexes for common queries; 3) Use prefix indexes and full-text indexes to optimize long string searches; 4) Regularly monitor and optimize indexes to keep indexes small and efficient. Through these methods, we can balance read and write performance and improve database efficiency.


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

SublimeText3 Linux new version
SublimeText3 Linux latest version

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
