Opening db connections

[=?ISO-8859-1?Q?Eduardo_Y=E1=F1ez_Parareda?=]

Hi,

when the connection to a DB is open, when you get the Statement or when you execute it?

ie.:

Statement stmt = StatementProvider.getStatement();
ResultSet rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");

Does this code mean 3 opened connection or only one (getStatement)?

 

[Lew]

when the connection to a DB is open, when you get the Statement or when
you execute it?

When you issue a DriverManager.getConnection(), typically, or via the
javax.persistence.EntityManager class.

ie.:

Statement stmt = StatementProvider.getStatement();
ResultSet rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");

Does this code mean 3 opened connection or only one (getStatement)?

It's no more than one, but not being familiar with the StatementProvider class
it's hard to be sure.

What is StatementProvider?

 

[Guest]

It's no more than one, but not being familiar with the StatementProvider

class it's hard to be sure.

What is StatementProvider?

I'm sorry, it's a class of my project, I didn't realize of that.

This is what I meant:

Connection conn = .... getConnection...

Statement stmt = conn.getStatement();
ResultSet rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");

 

[Lew]

I'm sorry, it's a class of my project, I didn't realize of that.

This is what I meant:

Connection conn = .... getConnection...

Statement stmt = conn.getStatement();
ResultSet rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");
rs = stmt.executeQuery("select 1");

You have as many connections as conn points to.
<http://java.sun.com/javase/6/docs/api/java/sql/DriverManager.html#getConnection(java.lang.String)>

<http://java.sun.com/javase/6/docs/api/java/sql/Connection.html>

and, of course, the Javadocs for ResultSet and Statement.

BTW, consider using a PreparedStatement instead of a "regular" Statement.