Connecting with MYSQL Database

[Mathew Mintalm]

Hello, Im trying to do this:

I have application connecting and getting data from Mysql database.

And i have problem to do this:

UPDATE table_name SET field_name1 =valueX WHERE field_name2

Ok, it works, but only if there is field_name2 with valueX

So when there isnt i would execute new statement with INSERT.

I know how to get data from mysql and so on, i just would request some help with already mentioned problem, check if field with given value exist, if yes update it with X in field Y, if not insert new ready entry with proper needed data.

Thanks in advance!

[Paul Clapham]

Mathew Mintalm wrote:check if field with given value exist, if yes update it with X in field Y, if not insert new ready entry with proper needed data.

Yes, that's correct, that's how you would do that. Did you have some question about it?

[Mathew Mintalm]

Thanks for reply

so i have to connect with database and use select statement, with try and catch exception, and in catch exception i should execute void which will create new entry (in case of exception)

?

[Paul Clapham]

I don't see where exceptions would come into the process. Do a SELECT which looks for the record which may or may not be there; if that query returns zero rows then it isn't there, so do an INSERT. If the query returns a row, then do an UPDATE.

[Mathew Mintalm]

Ok i guess i understand, could you please only show me this part of the code:

Do a SELECT which looks for the record which may or may not be there; if that query returns zero rows

?

[Paul Clapham]

I'm sorry... do you really not know how to execute a SELECT statement and read a row from it? That's usually the first example in any of the tutorials I ever saw.

[Mathew Mintalm]

I said i know, but i couldnt really example what did you mean with my previously quoted sentence.

do you meant something like that?

			statement = con.prepareStatement("SELECT * from table_name WHERE field1=0);
			rs = statement.executeQuery();
			
			int row = rs.getRow();
			
			if (row == 0)
			{

[Paul Clapham]

No. You actually have to try to read a row from the ResultSet.

rs = statement.executeQuery();
boolean thereIsARow = false;
if (rs.next()) {
  // If we get here then there must have been a row in the ResultSet
  thereIsARow = true;
}