Java sql doesnt show data without empty println

Question

I am using the following code from the internet to get data from a database:

ResultSet rs = statement.executeQuery();
ResultSetMetaData rsmd = rs.getMetaData();
System.out.println("querying SELECT * FROM XXX");
int columnsNumber = rsmd.getColumnCount();
while (rs.next()) {
    for (int i = 1; i <= columnsNumber; i++) {
        if (i > 1) System.out.print(",  ");
        String columnValue = rs.getString(i);
        System.out.print(columnValue + " " + rsmd.getColumnName(i));
    }
    System.out.println(""); //<-------------
}

Inside the while loop there is the empty println (arrow ^)

If I remove this empty println, the data doesnt show in my console, but if I leave it there it does (I have only one line in my database, so probably it just skips the last line if I have more data).

Why doesnt it show my single line of data if i leave out the empty println???

Thx!

The reason is just as you say, you have one line in your database. Have you tried to use `System.out.println(columnValue + " " + rsmd.getColumnName(i));` in your loop? Even try to move the `println` out of your while loop. — Pierre, Oct 21 '14 at 13:53
I totaly missed the print vs println, assuming everyone like me would use that because it gives cleaner console output in most cases. THX! — Randy, Oct 21 '14 at 13:58

score 2 · Accepted Answer · answered Oct 21 '14 at 13:55

2

The command line System.out is buffered, and only println does a flush(), emptying the buffer to the console.

In the loop you might do:

   if (i > 1) System.out.print(",  ");
   if (i % 5 == 1) System.out.println();

answered Oct 21 '14 at 13:55

Joop Eggen

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Java sql doesnt show data without empty println

1 Answers1