database-connection

问题 Why is database connection expensive to create ? Like what finite resource (bandwidth/network round trip/cpu) exactly is it consuming ? Typically expensive to create means it is consuming some resource like cpu/disk/io, but in case of connection i can only think of the time it takes for Sync/Ack etc. 回答1: You didn't say what database you are asking about, so this answer is pretty generic. Database connections are much more than just a TCP/IP socket. Each connection consumes memory that

问题 I want to connect to database in java web application.I wrote this code in servlet and i add related jar file(ojdbc) but when i run it,it gives me this error: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver public class DBConnection extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public DBConnection() { super(); // TODO Auto-generated constructor stub } public void service(HttpServletRequest request,

问题 I want to connect to database in java web application.I wrote this code in servlet and i add related jar file(ojdbc) but when i run it,it gives me this error: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver public class DBConnection extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public DBConnection() { super(); // TODO Auto-generated constructor stub } public void service(HttpServletRequest request,

问题 I have issue when i try to connect to the database on remote server. My code: const mysql = require('mysql'); const database = mysql.createPool({ host: 'localhost', user: 'user', password: 'pass', database: 'db' }); database.getConnection(function (err, connection) { if (!err) { console.log('Database is connected ...'); } else { console.log('Error connecting database ...'); } }); The credentials for connection in code is faked. With the right credentials I have, I login successfully on

问题 Every SQL Server connection string I ever see looks something like this: Data Source=MyLocalSqlServerInstance;Initial Catalog=My Nifty Database; Integrated Security=SSPI; Do I need the Initial Catalog setting? (Apparently not, since the app I'm working on appears to work without it.) Well, then, what's it for? 回答1: If the user name that is in the connection string has access to more then one database you have to specify the database you want the connection string to connect to. If your user

问题 Every SQL Server connection string I ever see looks something like this: Data Source=MyLocalSqlServerInstance;Initial Catalog=My Nifty Database; Integrated Security=SSPI; Do I need the Initial Catalog setting? (Apparently not, since the app I'm working on appears to work without it.) Well, then, what's it for? 回答1: If the user name that is in the connection string has access to more then one database you have to specify the database you want the connection string to connect to. If your user

问题 Hi I created one database in Oracle cloud . I am able to connect on the same via putty . But I am not able to connect from sqldeveloper . Below error is coming when I am trying the same. Can you please help me on the same 来源： https://stackoverflow.com/questions/60341154/error-while-connecting-dbaas-from-sql-developer-able-to-connect-from-putty

问题 Hi I created one database in Oracle cloud . I am able to connect on the same via putty . But I am not able to connect from sqldeveloper . Below error is coming when I am trying the same. Can you please help me on the same 来源： https://stackoverflow.com/questions/60341154/error-while-connecting-dbaas-from-sql-developer-able-to-connect-from-putty

问题 At our workplace, we have an ASP.NET application that uses Microsoft SQL Server 2016 Web Edition Database Server for the back-end database. At first, In the ASP.NET application web.config, I configured the Database Connection String to be: Password=blahPasswordblah; Persist Security Info=True; User ID=sa; Initial Catalog=yadaDatabaseNameyada; Data Source=blahDNSServerNameblah\yadaSQLServerInstanceNameyada It seemed to connect properly. However, I noticed something strange when the code in the

问题 I am developing NodeJS + MySQL web API. I am using mysql npm module. I want know connection is release or not is there any function or variable. Like if(!connection.isRelease() OR !connection.isClose() OR !connection.end()) { connection.release(); } Is there any specific function to know connection is release or not? I am getting error like "connection already release" 回答1: You can check if the connection is in the pool to see if it was released. The index in the free connections will be -1