Students who do application development often think that the database is operated and maintained by the DBA, and it is enough that they can write SQL. There is no need to learn database principles. In fact, even writing SQL requires understanding of database principles. For example, we all know that SQL query conditions should include […]
Tag: prepare
C++ encapsulates the C language MYSQL PrepareStatement interface (mysql_stmt_prepare)
example: auto stmt = pMysqlSession->findByIndex(StmtGMArenaSeasonPlayer::ID); auto pStmtData = static_cast<StmtGMArenaSeasonPlayer*>(stmt->getStmtData()); pStmtData->bindParams(fb->player_id(), fb->season_id()); stmt->exec(); int maxRank = 0; int count = 0; if (stmt->fetch()) { maxRank = pStmtData->get_max_rank(); count = pStmtData->get_count(); } Source File: StmtGMArenaCount::StmtGMArenaCount() : MysqlStmtData(ID, MYSQL_STMT_TYPE::PROCESS, “CALL cmd_arena_count(?,?,?,?,?);”) { clear(); } void StmtGMArenaCount::bind(MysqlPrepareStmt* pStmt) { pStmt->bind(DatabaseStmtBindArgs(DATABASE_STMT_BIND_TYPE_PARAM, DATABASE_STMT_TYPE::INT, 0, “params.m_begin_time”, & amp;params.m_begin_time, nullptr)); pStmt->bind(DatabaseStmtBindArgs(DATABASE_STMT_BIND_TYPE_PARAM, DATABASE_STMT_TYPE::INT, 1, […]
Using PreparedStatement to operate the database: query
We completed the common addition, deletion and modification operations for operating the database in the previous article. Now in this article we will implement the operation of querying the database. Take the customers table as an example Examples of query operations The operation of querying the database returns an additional result set compared to the […]
01-Prepare the environment to close the firewall service iptables status #Check whether service iptables stop is enabled #Temporarily close chkconfig ipta
01 – Prepare environment Turn off firewall service iptables status #Check whether it is enabled</code><code>service iptables stop #Temporarily closed</code><code>chkconfig iptables off #Permanently closed Turn off selinux setenforce 0 #Temporary shutdown</code><code>#Permanent shutdown requires modifying the configuration file</code><code>vim /etc/sysconfig/selinux Configure IP That is our host IP, which can be viewed through the ifconfig command. 02 – Install […]
Prepare our beloved IDEA to write Jsp
JSP learning 1. Prepare our beloved IDEA New project: New Project –> Next –>Next –>Finsh 2. Configure the server Tomcat-9.0.30 1.> Create a Lib package under WEB-INF Copy jsp-api.jar into it and make it effective Before taking effect: Effective process: 2.> Use hammer to configure TomCat Click the + sign to select the local Tom […]
vs+Qt(6.5) prepares the serial communication between the upper computer and the lower computer based on STC89R51RD+
Learning for the first time is both sharing and recording. Slave computer writing First, you need to have keil software and configure an environment that supports the STC89R51RD + chip, and then start configuring the serial port. Here we use the UART transmission protocol. Here is the configuration procedure: #include <REGX52.H> //Configure serial port void […]
Golang reports an error using sqlx that max_prepared_stmt_count exceeds 16382
Article directory background mysql preprocessing View instance preprocessing details com_stmt_prepare Turn on performance_schema View prepared statements locally Reasons for the spike in prepared statements Generate prepared statements but do not close An error occurred during execution of sql go service analysis Capture packets and analyze packets sent to mysql debug to view preprocessing details sqlx […]
Qt/C++ prepares video surveillance system 81-Onvif alarm capture and video recording and playback
1. Preface The graphic and text alarm module in the video surveillance system is obtained through event subscription of the Onvif protocol. After event subscription, various alarm events of the device, such as intrusion alarm/obstruction alarm/cross-border alarm/switch alarm, etc., are triggered. They will be actively sent to subscribers, and usually they will be sent twice, […]
Prepare to change jobs from now on – Bit Operations
I came across this sentence again while reviewing hashMap today: The length of the bucket array inside HashMap is always an integer number of 2. The advantages of this are: first, it can be quickly addressed through bit operations such as (table.length – 1) & key.hash(), and second, When HashMap is expanded, it can ensure […]
22 Python artificial intelligence libraries have been carefully prepared. It is recommended to collect them!
In order for everyone to have a preliminary understanding of the Python library commonly used for artificial intelligence, and to choose a library that can meet your own needs for study, a brief and comprehensive introduction to the currently more common artificial intelligence libraries will be given. 1. Numpy NumPy (Numerical Python) is an extension […]