database-connection

问题 is it be better to open connection to database - make any querys...update....delete - and after i use to close this connection or open the connection when the program load - and close when the program close ? thanks in advance 回答1: In general, you Close (Dispose) as soon as possible in your code. With a try/finally or using block. What actually happens depends on the ConnectionPool settings for your app. Basically the presence of the ConnectionPool means you don't have to worry about the

问题 is it be better to open connection to database - make any querys...update....delete - and after i use to close this connection or open the connection when the program load - and close when the program close ? thanks in advance 回答1: In general, you Close (Dispose) as soon as possible in your code. With a try/finally or using block. What actually happens depends on the ConnectionPool settings for your app. Basically the presence of the ConnectionPool means you don't have to worry about the

问题 I want to connect to Oracle database from C# but I can't Because this errors that ORA-12545: Connect failed because target host or object does not exist so how can i ? C# code string strConn = "Data Source =(DESCRIPTION =" + "(ADDRESS = (PROTOCOL = TCP)(HOST = DESKTOP-EIQ5MRF)(PORT = 1521))" + "(CONNECT_DATA =" + " (SERVER = DEDICATED)" + "(SERVICE_NAME = XE)" + ")" + ");User Id =system;password=bluesky;"; OracleConnection conn = new OracleConnection(strConn); conn.Open(); conn.Close();

问题 I want to write select and insert queries for 3 tables for the same database using a database connector. I want to know is there a alternative or how can it be done using 1 database connector? I ended up using 5 database connector. But I think this makes the flow look complicated. Is there any other way of doing this. 回答1: You are going in a wrong way :) It can be achieved by a single DB connector performing 3 different operations. Pls go through the documentation here :- https://docs

问题 When I try to connect to MS SQL, I got this error: > pyodbc.Error: ('08001', '[08001] [Microsoft][ODBC Driver 13 for SQL > Server]SQL Server Network Interfaces: Error Locating Server/Instance > Specified [xFFFFFFFF]. (-1) (SQLDriverConnect); [HYT00] > [Microsoft][ODBC Driver 13 for SQL Server]Login timeout expired (0); > [08001] [Microsoft][ODBC Driver 13 for SQL Server]A network-related or > instance-specific error has occurred while establishing a connection > to SQL Server. Server is not

问题 So i'm getting to grips with Django, or trying to. I have some code that isn't dependent on being called by the webpage - it's designed to populate the database with information. Eventually it will be set up as a cron job to run overnight. This is the first crack at it, which is to do an initial population (once I have that working, I'll move to an add structure, where only new records are pushed.) I'm using Python 2.7, Django 1.5 and Sqlite3. When I run this code, I get Requested setting

问题 Recently I have upgraded Django from version 1.6.5 to 1.7.1 and mysql-connector-python from 1.x to 2.0.2 After upgrading, the Exception(2013) is raised most of the time I make a query. Exception Type: InterfaceError Exception Value: (2013, '2013: Lost connection to MySQL server during query', None) I have added some settings about 'CONN_MAX_AGE', 'wait_timeout' but it does not help. Here are my settings: From command line: C:/>pip freeze Django==1.7.1 South==1.0.1 mysql-connector-python==2.0

问题 Recently I have upgraded Django from version 1.6.5 to 1.7.1 and mysql-connector-python from 1.x to 2.0.2 After upgrading, the Exception(2013) is raised most of the time I make a query. Exception Type: InterfaceError Exception Value: (2013, '2013: Lost connection to MySQL server during query', None) I have added some settings about 'CONN_MAX_AGE', 'wait_timeout' but it does not help. Here are my settings: From command line: C:/>pip freeze Django==1.7.1 South==1.0.1 mysql-connector-python==2.0

问题 We have a problem with org.springframework.jdbc.datasource.SingleConnectionDataSource ? We expect that the connection is never closed while the application is running, even if there is no traffic between application and db. We configured datasource with <property name="suppressClose" value="true"/> what should solve the problem. And the problem is that the connection is closed after about 30-40 minutes of inactivity (when there is no traffic between db and application). Maybe someone with

问题 We have a problem with org.springframework.jdbc.datasource.SingleConnectionDataSource ? We expect that the connection is never closed while the application is running, even if there is no traffic between application and db. We configured datasource with <property name="suppressClose" value="true"/> what should solve the problem. And the problem is that the connection is closed after about 30-40 minutes of inactivity (when there is no traffic between db and application). Maybe someone with