database-connection

问题 In my application I have a connection string in the config. This application created using .NET core 2.11 and SQL Server. This is the connection string: Data Source=servername\instancename, portnumber;Initial Catalog=dbname;Persist Security Info=True;User ID=username;Password=password; This string causes an error as shown here: This error happens if I use instance name and port number in the string. If I remove either one, it is working. So, how do I make it work to used both instance name

问题 I'm working on streamlining a bit our db helpers and utilities and I see that each of our functions such as for example findAllUsers(){....} or findCustomerById($id) {...} have their own connection details for example : function findAllUsers() { $srv = 'xx.xx.xx.xx'; $usr = 'username'; $pwd = 'password'; $db = 'database'; $port = 3306; $con = new mysqli($srv, $usr, $pwd, $db, $port); if ($con->connect_error) { die("Connection to DB failed: " . $con->connect_error); } else { sql = "SELECT *

问题 I'm working on streamlining a bit our db helpers and utilities and I see that each of our functions such as for example findAllUsers(){....} or findCustomerById($id) {...} have their own connection details for example : function findAllUsers() { $srv = 'xx.xx.xx.xx'; $usr = 'username'; $pwd = 'password'; $db = 'database'; $port = 3306; $con = new mysqli($srv, $usr, $pwd, $db, $port); if ($con->connect_error) { die("Connection to DB failed: " . $con->connect_error); } else { sql = "SELECT *

问题 When I click on the Create button to add a supplier record in to my database, I receive the above error message. Can someone help me where did I went wrong: is there something wrong with the insert statement. private void jbtnCreateActionPerformed(java.awt.event.ActionEvent evt) { try { String sql = "INSERT INTO supplier" +"(Full Name, Address Line 1, Address Line 2, Post Code, Email Address, Phone Number)" +"VALUES (?,?,?,?,?,?)"; connection = DriverManager.getConnection("jdbc:mysql:/

问题 The following are the different techniques we can use for database connection in a web application envrioment. Application Context Database Connection: only one database connection shared among all requests. Database Pooling: open a fixed number of database connection and share the connection among all requests. New Database Connection per request: Open a connection for each request. What are the advantage and disadvantage of these techniques? Which one should a developer use? 回答1: Option 1.

问题 The following are the different techniques we can use for database connection in a web application envrioment. Application Context Database Connection: only one database connection shared among all requests. Database Pooling: open a fixed number of database connection and share the connection among all requests. New Database Connection per request: Open a connection for each request. What are the advantage and disadvantage of these techniques? Which one should a developer use? 回答1: Option 1.

问题 I have a Python package that I am able to run successfully on an Azure Data Science Virtual Machine. However, when I push it to Azure as a Function, I cannot successfully make a database connection. I was getting an error that the ODBC Driver 13 for SQL Server was not supported, so I changed the driver to ODBC Driver 17 for SQL Server and now I am NOT getting an error, but no data is being returned for a query that I know should return data. Is there any other reason that data would not be

问题 In my Ubuntu VM, I kept getting SQLSTATE[HY000] [1045] Access denied for user 'username'@'localhost' (using password: YES) update I have configured my database like this in my .env file DB_HOST=45.55.88.57 DB_DATABASE=b-prod DB_USERNAME=root DB_PASSWORD=********* UNIX_SOCKET=/var/run/mysqld/mysqld.sock It works perfectly. But when I use DB_HOST=45.55.88.57 DB_DATABASE=b-prod DB_USERNAME=b <---------------------------------------------- DB_PASSWORD=********* UNIX_SOCKET=/var/run/mysqld/mysqld

问题 I am trying to connect dart with a MySQL database. I installed the MySQL workbench and created a simple DB, have modified the pubspec.yaml and added any other dependencies I needed for MySQL. But I keep pulling up an exception in the browser. EXCEPTION: Unsupported operation: RawSocket constructor STACKTRACE: dart:sdk_internal connect package:sqljocky5/comm/buffered_socket.dart 60:7 defaultSocketFactory package:sqljocky5/comm/buffered_socket.dart 72:20 connect dart:sdk_internal async package

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