database query size

[riches85]

If I execute a query in java, is there a way to determine the number of results without looping through the entire result set?

 

[Hattusas]

Unlikely.You have to find some other ways to find the number of records for that.DB2 with versions 7.1 and higher,gives the record number of an query with a function for example.

Salih Sipahi
Software Engineer.
City of Istanbul Turkey
s.sipahi@sahinlerholding.com.tr

 

[sedj]

The below linkshows the ResultSetMetaData class, which whild containing a lot of info, does contain methods for accessing row size.

http://java.sun.com/j2se/1.4.1/docs/api/java/sql/ResultSetMetaData.html

 

[venur]

Hi,

If you are looking for the size of the Resultset then you can use getFetchSize() of Resultset. Did I understood your question correctly ?

Cheers
Venu

 

[sedj]

Doh ! Of course.

 

[Hattusas]

Please examine this code below:
try{
Class.forName("COM.ibm.db2.jdbc.app.DB2Driver"
String url = "jdbc:db2:OGER2002" ;
java.sql.Connection connection = java.sql.DriverManager.getConnection(url, "db2admin", "db2admin"
java.sql.Statement stmt =connection.createStatement();
java.sql.ResultSet rs = stmt.executeQuery("select * from genparam.citylist"
System.out.println(rs.getFetchSize()+ "Fetch Size"
int i = 0;
while (rs.next()){
System.out.println(++i);
}
}
catch (Exception ex){
System.out.println(ex.toString());
}

That is taken from my database OGER2002 and genparam.citylist table.
Here is the console print messages of the code.
1Fetch Size
1
2
3
4
5
6
7
8
9
10
11
goes to 42 ( I didnt write it down up to 42 of course here)
the fetch size DOES NOT give you the number of records.
And size of a row DOES NOT mean the number of records also.
You can find number of columns,tables,foreign key by ResultSetMetaData but NOT this.

Salih Sipahi
Software Engineer.
City of Istanbul Turkey
s.sipahi@sahinlerholding.com.tr