database-connection

问题 When a database is down then automatically the ip and port switch to another db server. How should I configure c3p0 connection pooling of my web apps to follow this Database failover mechanism? Currently, I am using c3p0, however in the last db failover, pool connections failed to reestablished. 回答1: Reestablished after a failing request. Attributes that helps to come over as soon as possible p:testConnectionOnCheckin="true" p:preferredTestQuery="SELECT @@VERSION" p:acquireRetryAttempts="10"

问题 I am getting error 18456 from SQL Server Management Studio when I try to connect Windows Authentication or SQL Server Authentication as in the pictures below. Windows Authentication SQL Server Authentication I want to implement the solution in this link: Login to Microsoft SQL Server Error: 18456 but I can't start the engine in no way. Also, I don't know my password for SQL Server Authentication. What can I do? 回答1: I have seen this problem very often with SQL Server 2012 and later versions

问题 I want to make my code to be able to check if internet connection is established. After that I will normally save records in the database on the server, but I want to be able to save records in the local database on pc everytime the connection is lost and before every normal connection on the server check if the local database is empty and copy everything from local database to server database. Here is my code that I use now: //open database connection con = new MySqlConnection("server=192...

问题 I have certain initializing functions that I use to set up audit logging on the DB server side (ie, not rails) in PostgreSQL. At least one has to be issued (setting the current user) before inserting data into or updating any of the audited tables, or else the whole query will fail spectacularly. I can easily call these every time before running any save operation in the code, but DRY makes me think I should have the code repeated in as few places as possible, particularly since this diverges

问题 I'm running the following query in a PHP ODBC connection to a MSSQL sever: DECLARE @weekStart SMALLDATETIME; SET @weekStart = DATEADD(d,0, DATEDIFF(d,0,GETDATE())); -- weekStart = TODAY @ 00:00:00 -- per http://weblogs.sqlteam.com/jeffs/archive/2007/01/02/56079.aspx SET @weekStart = DATEADD(d, 1-DATEPART(dw, GETDATE()), @weekStart); -- subtract to last SUN @ 00:00:00 SELECT DATEDIFF(week, Run_Date, @weekStart) AS weeksAgo ,MIN(Current_List) AS list ,COUNT(*) AS cnt ,SUM(NoContact_90Days) AS

问题 I am using mysql connector.Python 1.0.9 downloaded from MySQL site. I have a sample table here DROP TABLE IF EXISTS my_table; CREATE TABLE my_table (id INT NOT NULL AUTO_INCREMENT UNIQUE, Shot VARCHAR(4), sec varchar(5), lay VARCHAR(15) NOT NULL, lay_status VARCHAR(15) NOT NULL, blk VARCHAR(10) NOT NULL, blk_status VARCHAR(15) NOT NULL, pri VARCHAR(10) NOT NULL, pri_status VARCHAR(15) NOT NULL, ani VARCHAR(10) NOT NULL, ani_status VARCHAR(15) NOT NULL, status VARCHAR(5) ); INSERT INTO my

问题 To connect to a SQLite database, it is reasonably straightforward: you pass a driver and a path to the SQLite file. For other DBI-compatible database backends (PostgreSQL, MySQL, etc.), what you can pass to dbConnect isn't obvious, nor well documented. How do I find out what I can pass to dbConnect to form the connection? 回答1: The arguments available depend upon the backend, which is why dbConnect only shows driver and ... arguments. Before we proceed, load the packages required for the

问题 To connect to a SQLite database, it is reasonably straightforward: you pass a driver and a path to the SQLite file. For other DBI-compatible database backends (PostgreSQL, MySQL, etc.), what you can pass to dbConnect isn't obvious, nor well documented. How do I find out what I can pass to dbConnect to form the connection? 回答1: The arguments available depend upon the backend, which is why dbConnect only shows driver and ... arguments. Before we proceed, load the packages required for the

问题 I just installed mysql on mac from Homebrew brew install mysql mysql -V mysql Ver 8.0.11 for osx10.13 on x86_64 (Homebrew) from terminal it works and I can login to mysql but from Sequel Pro it says Unable to connect to host 127.0.0.1, or the request timed out. Be sure that the address is correct and that you have the necessary privileges, or try increasing the connection timeout (currently 10 seconds). MySQL said: Authentication plugin 'caching_sha2_password' cannot be loaded: dlopen(/usr

问题 I just installed mysql on mac from Homebrew brew install mysql mysql -V mysql Ver 8.0.11 for osx10.13 on x86_64 (Homebrew) from terminal it works and I can login to mysql but from Sequel Pro it says Unable to connect to host 127.0.0.1, or the request timed out. Be sure that the address is correct and that you have the necessary privileges, or try increasing the connection timeout (currently 10 seconds). MySQL said: Authentication plugin 'caching_sha2_password' cannot be loaded: dlopen(/usr