database connection [closed]

1. Why is connection closed?
2. How do I check if my DB is closed?
3. What happens if DB connection is not closed?
4. How do you close a database connection?
5. What is DB connection leak?
6. How do I check if MySQL is open?
7. Should I close DB connection?
8. Should you keep database connection open?
9. Does using block close connection?
10. How do I kill all connections in a database?
11. How do you close a database connection in SQL?
12. Should I close database connection after each query?

Why is connection closed?

1 Answer. From the stack traces ,you are closing the connection while performing the insert after select. try creating the new connection. You might have called for closeConnection() method after select statement.So an exception is thrown at runtime when it tried to execute the query the connection is closed.

How do I check if my DB is closed?

The isClosed() method of the ResultSet interface is used to determine whether the current ResultSet object is closed.

What happens if DB connection is not closed?

It is tied to the database connection timeout. When a connection hasn't been used in a certain length of time, it can (sometimes) be recovered. The connection pool does not know whether the application has exited.

How do you close a database connection?

Long Answer:

1. in the left vertical menu, click on "Options"
2. Here you can find the checkbox saying, "close existing connections to destination database"

What is DB connection leak?

A connection leak occurs when a connection obtained from the pool was not closed explicitly by calling close() and then was disposed by the garbage collector and returned to the connection pool.

How do I check if MySQL is open?

Check database connection in MySQL using C#.

1. Step 1: Add Reference of MySql.Data.dll.
2. Step 2: Add a class file with named MYSQL.CS.
3. Step 3: Add the following name space. using MySql. Data. MySqlClient; using MySql. Data; ...
4. Step 5: To use above function please write the below code. Create instance of class: MYSQL mysql = new MYSQL(); Use it in Button event or anywhere.

Should I close DB connection?

We strongly recommend that you always close the connection when you are finished using it so that the connection will be returned to the pool.

Should you keep database connection open?

Absolutely it is safe to do this. This is how client-server applications work. If you are using a three-tier application, the application server will keep a pool of connections open anyway. ... Transactions could, however easily cover multiple acceses to the database, which is harder to do with a conneciton pool.

Does using block close connection?

The connection is automatically closed at the end of the using block.

How do I kill all connections in a database?

Kill All Connections Using Single User Mode

1. USE MASTER.
2. ALTER DATABASE [DatabaseName]
3. SET SINGLE_USER.
4. WITH ROLLBACK IMMEDIATE.
5. USE MASTER.
6. ALTER DATABASE [DatabaseName]
7. SET MULTI_USER.

How do you close a database connection in SQL?

Re: How do you close the connection at the SQL Server?

1. Right click on a database.
2. Click Delete in the context menu, which launches a dialog.
3. Select the "Close Connections" checkbox.
4. Click the menu item named "Script to new query window"

Should I close database connection after each query?

If you create one per query / transaction, it is much easier to manage "closing" the connections. I can see why common sense dictates that you should open one and use it throughout, but you will run into problems with dropped connections and multithreading.