To count no of rows returned into ResultSet

How to count the no of rows of a resultset

Try this way
rs = stmt.executeQuery(query);
rs.last(); //move to the last row
numRows = rs.getRow(); // equal to row count
rs.beforeFirst(); // set the position of the cursor before the the first record for processing

Similar Messages

Getting the number of rows returned from ResultSet

Hi,
Does anyone know a method to get the number of rows returned with a query using the Resultset class?
Thanks.

Hi 281080,
If your database and JDBC driver support it, in order to use the solution that da-alexj has suggested, you need to create a 'scrollable' "ResultSet" -- the javadoc for method "createStatement()" (in class "java.sql.Connection") has more details.
However, I have found with Oracle 8.1.7.4 database and Oracle (thin) JDBC driver, that part of their implementation of the "last()" method (in class "java.sql.ResultSet") is to actually iterate through the entire "ResultSet" in order to reach the last row. If your "ResultSet" is very large (I tested it with a 100,000 row "ResultSet"), this will take a long time.
Just wanted to make you aware of that.
Of-course, this may be irrelevant to you since I didn't see any mention in your post of what database and JDBC driver you are using.
Hope this has helped you, anyway.
Good Luck,
Avi.

How to run a select count(*) with multiple rows returned

Hi,
I have to run a select count(*) for different reports.
1) Select count(*) from table
where state = 'CA'
2) Select count(*) from table
where state = 'NY'
3) Select count(*) from table
where state = 'NV'
Instead of running this query again for 50 times, is there a way for me to just put it in one query and get multiple row returns? Thank you.

Samantha wrote:
Hi,
I have to run a select count(*) for different reports.
1) Select count(*) from table
where state = 'CA'
2) Select count(*) from table
where state = 'NY'
3) Select count(*) from table
where state = 'NV'
Instead of running this query again for 50 times, is there a way for me to just put it in one query and get multiple row returns? Thank you.select state, count(*) from table group by state order by 1;

Returning a subset of rows through a ResultSet WITHOUT rownum?

I am trying to figure out a way to get a subset of rows from a ResultSet (or ResultSet equivalent) without using rownum and without sending all the rows before the requested row over the wire.
My problem is this: I am not in control of the SQL that is sent to the database. It is autogenerated by a third party tool (TOPLink). Therefore using the rownum solution isn't practical. My steps of operation are:
1. Get SQL from TOPLink
2. Pass SQL through a Statement
3. Get resulting ResultSet
At this point, I want to say, "Mr. ResultSet, I only want rows 200-250." And I then want Mr. ResultSet to fetch only rows 200 to 250, and no others. I don't want to see rows 1 to 199 coming over the wire.
Anyone have any ideas? Is this possible at all? Also, if there's a way to do this through the TOPLink mechanisms (ScrollableCursors and ReportQuery objects and whatnot), please do let me know. I have tried using the TOPLink facilities, and sure enough rows 1 to 199 flow across the network.
Thanks,
Michael Allen
[email protected]

Hi Michael,
Is there some sort of selection criteria in which you could use return the required 200-250 rows of data? If so, I would embed that into the TopLink query.
Another option is using the ORDER BY operator. Without order, constructing a query of elements 200-250 twice would not guarentee that they would be the same elements.
You can also construct your own SQL statement and execute it directly on a TopLink session.
Darren Melanson
Strategic Implementation Consultant
Oracle Canada.
I am trying to figure out a way to get a subset of rows from a ResultSet (or ResultSet equivalent) without using rownum and without sending all the rows before the requested row over the wire.
My problem is this: I am not in control of the SQL that is sent to the database. It is autogenerated by a third party tool (TOPLink). Therefore using the rownum solution isn't practical. My steps of operation are:
1. Get SQL from TOPLink
2. Pass SQL through a Statement
3. Get resulting ResultSet
At this point, I want to say, "Mr. ResultSet, I only want rows 200-250." And I then want Mr. ResultSet to fetch only rows 200 to 250, and no others. I don't want to see rows 1 to 199 coming over the wire.
Anyone have any ideas? Is this possible at all? Also, if there's a way to do this through the TOPLink mechanisms (ScrollableCursors and ReportQuery objects and whatnot), please do let me know. I have tried using the TOPLink facilities, and sure enough rows 1 to 199 flow across the network.
Thanks,
Michael Allen
[email protected]

How do you return the number of Rows in a ResultSet??

How do you return the number of Rows in a ResultSet? It's easy enough to do in the SQL query using COUNT(*) but surely JDBC provides a method to return the number of rows.
The ResultSetMetaData interface provides a method for counting the number of columns but nothing for the rows.
Thanks

No good way before JDBC2.0. u can use JDBC2.0 CachedRowSet.size() to retrieve the number of rows got by a ResultSet.

Counting Rows from a ResultSet

Hi!
If I retreive some information from a database, say by using:
ResultSet RS = Stmt.executeQuery("select * from events");How can I get a value for the amount of rows in this ResultSet?
Thanks!
Alastair

Almost everyone, when they first use ResultSet thinks of it as a container with the data rows already in there, and wonders why there's no size method.
But that's not how they work. A ResultSet, generally, holds only one row at a time. next requests the next row from the database and before next is called the ResultSet doesn't know if another row is going to be available. Indeed the number of rows that qualify for return in the result set may actually change while you are processing it.
Doing the SELECT COUNT(*) request asks the database for the number of rows that match any criteria in the SELECT, but that number may have changed when you actually retrieve the rows. Someone else may have added or removed rows.

Is it possible to count the rows returned from a query?

Hello,
When using JDBC is there anyway of finding out the number of
rows returned from a query before actually getting each row?
In Forms 4.5 you can use the count_query function, does anyone
know of an equivalent function or work around in JDBC and/or
SQLJ?
Thanks.
null

Pasi Hmlinen (guest) wrote:
: Try
: SELECT COUNT(*) FROM the_table WHERE <conditions>;
: Hope this helps,
: Pasi
Thanks for the advice, I'm currently using SELECT COUNT(*) but
I'm looking for a more efficient way of doing it. If I SELECT
COUNT each time then I have to prepare and execute a SQL
statement each time. What I want to do it execute a single SQL
statement to return my results and somehow find out the number
of rows in the resultset without having to go back to the
database.
Gethin.
null

Getting # of rows returned in JDBC resultset

Hi,
Is there an easy call to get the number of rows in a resultset?
Right now I want to display en entire record if there's only one and display only a subset of record info if there's more than one.
I ended up doing the following:
while(rs.next()) {
i++);
then I call rs.beforeFirst(); to get back to the beginning of the result set and set my conditionals to operate on the "i" variable I created before.
There must be a rs.maxcount() or something to that effect isn't there? I'm using a JDBC2.0 type 4 postgreSQL driver. It supports Datasourcing, but not much else.
Frank

Hi,
You can do it in two ways,
1. As stated above, you can do it.
For more information,
http://java.sun.com/j2se/1.3/docs/api/java/sql/ResultSet.html
2.You can use a seperate prepared statement that returns nothing but a count of the rows that will be selected. i.e. select count(*) from Table,
Instead of * you can also use any column existing in Table.
Hope this helps.
Best Luck!
Senthil Babu J

Getting the no. of rows returned from the resultset

Could somebody tell how can I get the count of rows from the resultset object.
Thanks a lot in advance

hmmm 20,710 topics and 69,000 odd posts and no one has EVER asked this question before.. it's a miracle....
or maybe it has been asked and dealt with approx... 11,000 times.
here is a discussion from 1998 for example http://forum.java.sun.com/thread.jsp?forum=48&thread=83958

DBMS_MVIEW.ESTIMATE_MVIEW_SIZE rows returned different that the count of..

Hi,
I have done the following...
1.Gathered table stats...
SQL> EXEC DBMS_STATS.GATHER_TABLE_STATS('SCOTT','STRDET');
PL/SQL Procedure executed successfully
SQL> EXEC DBMS_STATS.GATHER_TABLE_STATS('SCOTT','DETAILS_DET');
PL/SQL Procedure executed successfully
2. Executed the following anonymous PL/SQL block:
SQL> set serveroutput on size 999999
SQL> declare
2     l_num_rows number;
3     l_num_bytes number;
4     l_stmt      varchar2(2000);
5 begin
6     l_stmt := 'select grp,
7              sum(purchcontyear0) , sum(PURCHAPPRREQYEAR0)
8        from (
9               select connect_by_root s.costcenterms grp,
10                       d.purchcontyear0 , PURCHAPPRREQYEAR0
11                 from strdet s,
12                       details_det d
13                      where s.costcenterdet=d.costcenterms(+)
14                      connect by s.costcenterms = prior s.costcenterdet
15             )
16       group by grp';
17     dbms_mview.estimate_mview_size
18     (
19        stmt_id       => 'Est1',
20        select_clause => l_stmt,
21        num_rows      => l_num_rows,
22        num_bytes     => l_num_bytes
23     );
24     dbms_output.put_line('Number of rows = '||l_num_rows);
25     dbms_output.put_line('Size (bytes) = '||l_num_bytes);
26 end;
27 /
Number of rows = 12
Size (bytes) = 1248
3. Executed the sql script ...
SQL> select count(*)
2 from
3 (
4   select grp,
5              sum(purchcontyear0) , sum(PURCHAPPRREQYEAR0)
6        from (
7               select connect_by_root s.costcenterms grp,
8                       d.purchcontyear0 , PURCHAPPRREQYEAR0
9                 from strdet s,
10                       details_det d
11                      where s.costcenterdet=d.costcenterms(+)
12                      connect by s.costcenterms = prior s.costcenterdet
13             )
14       group by grp
15 )
16 /
COUNT()*
         *6*According to the Oracle Doc...
Oracle® Database PL/SQL Packages and Types Reference
10g Release 2 (10.2)
Part Number B14258-01
ESTIMATE_MVIEW_SIZE Procedure
This procedure estimates the size of a materialized view that you might create, in bytes and number of rows.Can anybody explain why is there so much difference in number of rows...even though i gathered freshed table stats regarding the source table....???? and how to , if possible , make the estimation more precise...????
NOTE: The above is just a wonder.....
Many thanks...
Sim

Hi,
SQL> create table dup as select * from user_objects;
Table created.
SQL> insert into dup select * from dup;
7 rows created.
SQL> /
14 rows created.
SQL> /
28 rows created.
SQL> /
56 rows created.
SQL> /
112 rows created.
SQL> /
224 rows created.
SQL> /
448 rows created.
SQL> commit;
Commit complete.
SQL> desc dup
Name                                      Null?    Type
OBJECT_NAME                                        VARCHAR2(128)
SUBOBJECT_NAME                                     VARCHAR2(30)
OBJECT_ID                                          NUMBER
DATA_OBJECT_ID                                     NUMBER
OBJECT_TYPE                                        VARCHAR2(19)
CREATED                                            DATE
LAST_DDL_TIME                                      DATE
TIMESTAMP                                          VARCHAR2(19)
STATUS                                             VARCHAR2(7)
TEMPORARY                                          VARCHAR2(1)
GENERATED                                          VARCHAR2(1)
SECONDARY                                          VARCHAR2(1)
SQL> EXEC DBMS_STATS.GATHER_TABLE_STATS('SCOTT','DUP');
PL/SQL procedure successfully completed.
SQL> DECLARE
2   out_rows   NUMBER;
3   out_bytes NUMBER;
4 BEGIN
5    dbms_mview.estimate_mview_size('abc',
6    'SELECT * FROM DUP', out_rows, out_bytes);
7
8    dbms_output.put_line(out_rows);
9    dbms_output.put_line(out_bytes);
10 END;
11 /
896
236544
PL/SQL procedure successfully completed.
SQL> select count(*) FROM DUP;
COUNT(*)
       896
1 row selected.
SQL>Can you check your query once...
- Pavan Kumar N

Number of rows returned by the resultset is wrong

Hi All,
I have pasted the code i used for JDBC. The problem is the number of rows returned by the resultset is 5 times that of the original data. Is something wrong with my code. Can anyone pls point out the mistake I have done if any.
    public ArrayList dataBreakup(String team, int monthNo, int year) {         String sqlDataBreakup = "";         Connection con1 = null;         Statement stmt = null;         ResultSet rs = null;         ArrayList data = new ArrayList();         int noRows = 0;         Calendar cal = Calendar.getInstance();         Calendar cal2 = new GregorianCalendar(cal.get(Calendar.YEAR), monthNo, 1);         int days = cal2.getActualMaximum(cal2.DAY_OF_MONTH);         String start_date = "01-Jan-" + year;         String end_date = days + "-" + monthName[cal2.get(Calendar.MONTH)] + "-" + cal2.get(cal2.YEAR);         System.out.println("START: " + start_date);         System.out.println("END: " + end_date);         databaseConnection dbObject = new databaseConnection();         try {             con1 = dbObject.GetConnection();             stmt = con1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);             sqlDataBreakup = "Select * from EXPENSE_STORE WHERE " +                     "team='" + team + "'AND category != 'Pending PO''s' AND ACCOUNTING_DATE " +                     "BETWEEN to_date('" + start_date + "') AND to_date('" + end_date + "')";             rs = stmt.executeQuery(sqlDataBreakup);                         ResultSetMetaData rsmd = rs.getMetaData();             int numColumns = rsmd.getColumnCount();             data.add(numColumns);             for (int i = 1; i < numColumns + 1; i++) {                 data.add(rsmd.getColumnName(i));             }                        while (rs.next()) {                                noRows++;                 for (int i = 1; i < numColumns + 1; i++) {                     switch (rsmd.getColumnType(i)) {                         case java.sql.Types.NUMERIC:                             data.add(rs.getFloat(i));                             break;                         case java.sql.Types.DATE:                             data.add(rs.getDate(i));                             break;                         default:                             data.add(rs.getString(i));                             break;                     }                                    }                     }             data.add(1, noRows);             rs.close();         } catch (SQLException SQLe) {             System.out.println("DumpData() : SQL Exception" + SQLe.getMessage());             SQLe.printStackTrace();         } catch (Exception e) {             System.out.println("DumpData() : Other Exception");             e.printStackTrace();         } finally {             dbObject.CloseConnection(con1);         }         return data;     }
Thanks
Cheers N...

Only thing i can say is
try the following
replace your function by this one and tell us the console output of the same
public ArrayList dataBreakup(String team, int monthNo, int year) {
        String sqlDataBreakup = "";
        Connection con = null;
        ArrayList data = new ArrayList();
        int noRows = 0;
        Calendar cal = Calendar.getInstance();
        Calendar cal2 = new GregorianCalendar(cal.get(Calendar.YEAR), monthNo, 1);
        int days = cal2.getActualMaximum(cal2.DAY_OF_MONTH);
        String start_date = "01-Jan-" + year;
        String end_date = days + "-" + monthName[cal2.get(Calendar.MONTH)] + "-" + cal2.get(cal2.YEAR);
        System.out.println("START: " + start_date);
        System.out.println("END: " + end_date);
        System.out.println("START: " + start_date);
        System.out.println("END: " + end_date);
        databaseConnection dbObject = new databaseConnection();
        try {
            con = dbObject.GetConnection();
            sqlDataBreakup = "Select * from EXPENSE_STORE WHERE " +
                    "team = '"+team+"' AND category != 'Pending PO''s' AND ACCOUNTING_DATE " +
                    "BETWEEN to_date('"+start_date+"') AND to_date('"+end_date+"')";
               System.out.println("-----------sql starts---------------");
               System.out.println(sqlDataBreakup);
               System.out.println("-----------sql ends---------------");
            PreparedStatement pstmt = con.prepareStatement(sqlDataBreakup);
               pstmt.setString(1, team);
            pstmt.setString(2, start_date);
            pstmt.setString(3, end_date);
            ResultSet rs = pstmt.executeQuery();
            ResultSetMetaData rsmd = rs.getMetaData();
            int numColumns = rsmd.getColumnCount();
            data.add(numColumns);
            for (int i = 1; i < numColumns + 1; i++) {
                data.add(rsmd.getColumnName(i));
            while (rs.next()) {
                noRows++;
                for (int i = 1; i < numColumns + 1; i++) {
                    switch (rsmd.getColumnType(i)) {
                        case java.sql.Types.NUMERIC:
                            data.add(rs.getFloat(i));
                            break;
                        case java.sql.Types.DATE:
                            data.add(rs.getDate(i));
                            break;
                        default:
                            data.add(rs.getString(i));
                            break;
            //data.add(1, noRows);
               System.out.println("no of Rows : " +noRows );
        } catch (SQLException SQLe) {
            System.out.println("DumpData() : SQL Exception" + SQLe.getMessage());
            SQLe.printStackTrace();
        } catch (Exception e) {
            System.out.println("DumpData() : Other Exception");
            e.printStackTrace();
        } finally {
            dbObject.CloseConnection(con);
        return data;
    }and try running the sql printed on the screen in your db and then let us know the result.
in this code i have removed some of your code in order to simplify the problem.

Counting the rows in a ResultSet

I am wondering how I could find out the number of rows in a ResultSet after performing a query?

In case anyone's curious I figured out the problem. The ResultSet needs to be set to move forward AND backward. This is done as follows:
Statement stmt = conn.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);

Trying to get the last row from a resultset

Hi,
I'm trying to do a query to postgreSQL and have it return the last updated value, (last row).
My prepared statement is returning the correct results, but i'm having a problem getting the latest value.
I'm using a comboBox to drive a textfield, to load the last entered values in depending on which item in the comboBox is selected.
I've tried a variety of things and most seem to return the first row, not showing the updated values.
Or, if it does work, it takes to long to load, and i get an error.
here is the working code;
Object m = machCBX.getSelectedItem():
try { PreparedStatment last = conn.prepareStatement("SELECT part, count FROM production WHERE machine = ?",
ResultSet.TYPE_SCROLL_INSENSITIVE, //tried both INSENSITIVE and SENSITIVE
ResultSet.CONCUR_READ_ONLY);
last.setString(1, String.valueOf(m));
rs. = last.executeQuery();
if(rs.isAfterLast) == false ) {
rs.afterLast();
while(rs.previous()) {
String p = rs.getString("part");
int c = rs.getInt("count");
partJTX.setText(p);
countJTX.setText(c);
}this grabs values, but they are not the last entered values.
Now if i try to use rs.last() it returns the value i'm looking for but takes to long, and i get:
Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space I also know using ra.last() isn't the best way to go.
I'm just wondering if there is another way other than getting into vectors and row count? or am i better off to go with the later?
thanks
-PD

OK, you've got a major misunderstanding...
The relational database model is built on the storage of sets - UNORDERED sets. In other words, when you hand a database a SELECT statement without an ORDER BY clause, the database is free to return the results in any order.
Now it so happens that most databases will happen to return data retrieved by an unordered SELECT, at least for a while, in the same order that it was inserted, especially if no UPDATE or DELETE activity has occured, and no database maintenance has occured. However, eventually most tables have some operation that creates a "space" in the underlying storage, or causes a row to expand and have to be moved or extended, or something. Then the database will start returning unordered results in a different order. If you (or other people) never ever ever UPDATE or DELETE a table, then on some databases the data might well come out in insertion order for a very very long time; given human nature and the way projects tend to work, relying on that is a sucker's bet, IMHO.
In other words, if you want the "most recent" something, you need to store a timestamp with your data. (With some databases, you might be able to take advantage of some non-standard feature to get "last updates" or "row change timestamps", but I know of no such for Postgres.
While this won't solve your major problem, above, your issue with rs.last is probably occuring because Postgres by default will prefetch your entire ResultSet. Use Statement.setFetchSize() to change that (PreparedStatement inherits the method, of course).

Need to know how to limit the number of rows returned on Oracle

MS SQL Server has a command called 'set row count'.
We are trying to find similar one on Oracle.
What we are trying to do is that instead of using rownum in the query statement, we would like to find way to limit the number of rows returned. I understand that we can use JDBC resultSet object, but that's not what we want.
I know Oracle has one called arraysize, but this would not limit the number of rows returned either.
Pease help.
Thanks

I understand that we can use JDBC resultSet object, but that's not what we want.I'm not sure which feature of ResultSet you use and which not.
But if this question has anything to do with JDBC (that's the forum where you put it), I'd recommend to use Statement.setMaxRows(). This will limit the count of rows which your statement will fetch into it's ResultSet.

[Forum FAQ] How do I send multiple rows returned by Execute SQL Task as Email content in SQL Server Integration Services?

Question:
There is a scenario that users want to send multiple rows returned by Execute SQL Task as Email content to send to someone. With Execute SQL Task, the Full result set is used when the query returns multiple rows, it must map to a variable of the Object data
type, then the return result is a rowset object, so we cannot directly send the result variable as Email content. Is there a way that we can extract the table row values that are stored in the Object variable as Email content to send to someone?
Answer:
To achieve this requirement, we can use a Foreach Loop container to extract the table row values that are stored in the Object variable into package variables, then use a Script Task to write the data stored in packages variables to a variable, and then set
the variable as MessageSource in the Send Mail Task.
Add four variables in the package as below:
Double-click the Execute SQL Task to open the Execute SQL Task Editor, then change the ResultSet property to “Full result set”. Assuming that the SQL Statement like below:
SELECT   Category, CntRecords
FROM         [table_name]
In the Result Set pane, add a result like below (please note that we must use 0 as the result set name when the result set type is Full result set):
Drag a Foreach Loop Container connects to the Execute SQL Task.
Double-click the Foreach Loop Container to open the Foreach Loop Editor, in the Collection tab, change the Enumerator to Foreach ADO Enumerator, then select User:result as ADO object source variable.
Click the Variable Mappings pane, add two Variables as below:
Drag a Script Task within the Foreach Loop Container.
The C# code that can be used only in SSIS 2008 and above in Script Task as below:
public void Main()
   // TODO: Add your code here
            Variables varCollection = null;
            string message = string.Empty;
            Dts.VariableDispenser.LockForWrite("User::Message");
            Dts.VariableDispenser.LockForWrite("User::Category");
            Dts.VariableDispenser.LockForWrite("User::CntRecords");
            Dts.VariableDispenser.GetVariables(ref varCollection);
            //Format the query result with tab delimiters
            message = string.Format("{0}\t{1}\n",
                                        varCollection["User::Category"].Value,
                                        varCollection["User::CntRecords"].Value
           varCollection["User::Message"].Value = varCollection["User::Message"].Value + message;
           Dts.TaskResult = (int)ScriptResults.Success;
The VB code that can be used only in SSIS 2005 and above in Script Task as below, please note that in SSIS 2005, we should
change PrecompileScriptIntoBinaryCode property to False and Run64BitRuntime property to False
Public Sub Main()
        ' Add your code here
        Dim varCollection As Variables = Nothing
        Dim message As String = String.Empty
        Dts.VariableDispenser.LockForWrite("User::Message")
        Dts.VariableDispenser.LockForWrite("User::Category")
        Dts.VariableDispenser.LockForWrite("User::CntRecords")
        Dts.VariableDispenser.GetVariables(varCollection)
        'Format the query result with tab delimiters
        message = String.Format("{0}" & vbTab & "{1}" & vbLf, varCollection("User::Category").Value, varCollection("User::CntRecords").Value)
        varCollection("User::Message").Value = DirectCast(varCollection("User::Message").Value,String) + message
        Dts.TaskResult = ScriptResults.Success
End Sub
Drag Send Mail Task to Control Flow pane and connect it to Foreach Loop Container.
Double-click the Send Mail Task to specify the appropriate settings, then in the Expressions tab, use the Message variable as the MessageSource Property as below:
The final design surface like below:
References:
Result Sets in the Execute SQL Task
Applies to:
Integration Services 2005
Integration Services 2008
Integration Services 2008 R2
Integration Services 2012
Integration Services 2014
Please click to vote if the post helps you. This can be beneficial to other community members reading the thread.

Thanks,
Is this a supported scenario, or does it use unsupported features?
For example, can we call exec [ReportServer].dbo.AddEvent @EventType='TimedSubscription', @EventData='b64ce7ec-d598-45cd-bbc2-ea202e0c129d'
in a supported way?
Thanks! Josh

To count no of rows returned into ResultSet

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