How to retrieve number of rows of a table by jdbc?
can anyone show me a simple snippet of a java code about how to retrieve the number of ROWS in a table?
or even only showing the jdbc command that does this job would be enough.
thanks in advance :)
cheers
1. query for the count, then execute the query
"select count(*) from test" then
"select * from test"
2. create a scrollable ResultSet then
rs.last();
int count = rs.getRow();
rs.beforeFirst();
Jamie
p.s. this topic has been discussed MANY times. Do a search on this forum and you will get lots of other discussions on this topic.
Similar Messages
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How to find number of rows in a table
i have one table ,it contains millions of record,how can i know number of rows in that table without using count(*),
i tried in user_table ,for the column NUM_ROWS,but it is not showing number of rows,pls send me a solution for this.
regards,
singhOk, that only was to show simply that max option
might not an option to reduce execution time.Yes, but I/O variances have a tendency to really skew the observed elapsed execution time - making execution time alone a poor choice to determine what SQL will perform better than another.
Both MAX(ROWNUM) and COUNT(*) results in the same amount of I/O - as both uses the exact same execution plan, I/O wise. In this example, a FTS.
SQL> create table testtab nologging as select * from all_objects where rownum < 10001;
Table created.
-- warmed up the buffer cache with a couple of SELECTs against TESTAB in order
-- to discard PIOs from the results
SQL> set autotrace on
SQL> select count(*) from testtab;
COUNT(*)
10000
Execution Plan
Plan hash value: 2656308840
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1 | 35 (9)| 00:00:01 |
| 1 | SORT AGGREGATE | | 1 | | |
| 2 | TABLE ACCESS FULL| TESTTAB | 9262 | 35 (9)| 00:00:01 |
Note
- dynamic sampling used for this statement
Statistics
0 recursive calls
0 db block gets
131 consistent gets
0 physical reads
0 redo size
223 bytes sent via SQL*Net to client
238 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
SQL> select max(rownum) from testtab;
MAX(ROWNUM)
10000
Execution Plan
Plan hash value: 2387991791
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1 | 35 (9)| 00:00:01 |
| 1 | SORT AGGREGATE | | 1 | | |
| 2 | COUNT | | | | |
| 3 | TABLE ACCESS FULL| TESTTAB | 9262 | 35 (9)| 00:00:01 |
Note
- dynamic sampling used for this statement
Statistics
0 recursive calls
0 db block gets
131 consistent gets
0 physical reads
0 redo size
225 bytes sent via SQL*Net to client
238 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
So seeing that we have the exact same baseline for both queries, and that PIO does not influence the results, we time a 1000 executions of both.
SQL> declare
2 cnt number;
3 begin
4 for i in 1..1000
5 loop
6 select count(*) into cnt from testtab;
7 end loop;
8 end;
9 /
PL/SQL procedure successfully completed.
Elapsed: 00:00:03.19
SQL>
SQL> declare
2 cnt number;
3 begin
4 for i in 1..1000
5 loop
6 select max(rownum) into cnt from testtab;
7 end loop;
8 end;
9 /
PL/SQL procedure successfully completed.
Elapsed: 00:00:15.87
SQL>
This shows that what makes the MAX() more expensive is just that - determining the MAX(). For each row, Oracle has to call its internal MAX() function with two values - the current max result and the new value. This function then returns the new max value. This overhead per row adds up to a significant overhead in execution time - making the MAX() approach 5x slower than the COUNT() approach. -
How to set number of Rows of a table to be displayed based on user action?
Hi Experts,
I am getting data into the table. But only 5 records are displayed default. I want it to be a user selection.
If user wishes to see 10 records, then first 10 records should get displayed. If user selects 'n' records then 'n' records should get displayed..
How to achieve this?
Regards,
Yugesh A.hi Yugesh ,
1 create a input field UI
2 bind its value property to a attribute
3 suppose ca_check attribute ( type string ) under node cn_check is binded
read this in ur doinit of the view
DATA lo_nd_cn_check TYPE REF TO if_wd_context_node.
DATA lo_el_cn_check TYPE REF TO if_wd_context_element.
DATA ls_cn_check TYPE wd_this->element_cn_check.
DATA lv_ca_check LIKE ls_cn_check-ca_check.
* navigate from <CONTEXT> to <CN_CHECK> via lead selection
lo_nd_cn_check = wd_context->get_child_node( name = wd_this->wdctx_cn_check ).
* get element via lead selection
lo_el_cn_check = lo_nd_cn_check->get_element( ).
* get single attribute
lo_el_cn_check->get_attribute(
EXPORTING
name = `CA_CHECK`
IMPORTING
value = lv_ca_check ).
4 nw for ur table , make a another context attribute of type either string or I , say attr1
bind its visiblerowcount property of table to attr1
5 make a attribute in ATTRIBUTES tab of type string , say attribute
set its value to lv_ca_check in doinit itself
wd_this->attribute = lv_ca_Check
6 nw in the method , where u need to validate how m,any rows user enter or doinit itself , set attr1 to the value of that attribute created under ATTRIBUTES tab ( named attribute)
DATA : lv_count type string .
lv_count = wd_this->attribute
7 nw its very simple , set attr1 to lv_count , as it contains the count of the number which has entered in the input field
DATA lo_nd_cn_check TYPE REF TO if_wd_context_node.
DATA lo_el_cn_check TYPE REF TO if_wd_context_element.
DATA ls_cn_check TYPE wd_this->element_cn_check.
DATA attr1 LIKE ls_cn_check-ca_check.
* navigate from <CONTEXT> to <CN_CHECK> via lead selection
lo_nd_cn_check = wd_context->get_child_node( name = wd_this->wdctx_cn_check ).
* get element via lead selection
lo_el_cn_check = lo_nd_cn_check->get_element( ).
* set single attribute
lo_el_cn_check->set_attribute(
EXPORTING
name = `attr1`
value = lv_count ).
I hope it shud help
proceed like these , u wud be able to achieve the desired functionality
regards,
amit
Edited by: amit saini on Oct 20, 2009 1:12 PM -
How to retrieve the multiple rows data on PDF form in a web service method using WSDL DataConnection
How to retrieve the multiple rows data on PDF form in a web service method using WSDL DataConnection.
I have a multiple rows on PDF form. All rows have 4 textfields. I want to submit the multiple rows data to a method defiened in webservice.
Unable to retrieve the data in multiple rows within webservice method.Hi Paul,
I'm now able to save the retrieved xml in a hidden text field and create dynamic table, and I'm able to fill this table from the XML, but the problem is that I could not find the correct way to loop on the xml, what I'm trying to say, the table will have number of rows with the data of the first row only, so can you tell me the right way to loop on the xml!
this is my code
TextField1.rawValue=xmlData.document.rawValue;
xfa.datasets.data.loadXML(TextField1.rawValue, true, false);
for(var i=0; i<count; i++)
xfa.form.resolveNode("form1.P1.Table1.Row1["+i+"].Num").rawValue = xfa.datasets.data.record.num.value;
xfa.form.resolveNode("form1.P1.Table1.Row1["+i+"].Name").rawValue = xfa.datasets.data.record.name.value;
Table1.Row1.instanceManager.addInstance(true);
Thanks
Hussam -
How to get number of rows return in SELECT query
i'm very new in java, i have a question:
- How to get number of rows return in SELECT query?
(i use SQL Server 2000 Driver for JDBC and everything are done, i only want to know problems above)
Thanks.make the result set scroll insensitve, do rs.last(), get the row num, and call rs.beforeFirst(), then you can process the result set like you currently do.
String sql = "select * from testing";
PreparedStatement ps =
con.prepareStatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
ResultSet rs = ps.executeQuery();
rs.last();
System.out.println("Row count = " + rs.getRow());
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All
How to restrict number of rows display using <ig:gridView datasource="{mybean.mylist}">
i am getting 10 rows using data_row . i wanna show only first 5 rows .
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thanks
rambhapuriI have no idea which component you're talking about. If want to discuss here about a non-Sun JSF component, then please mention about the name, version and build in detail. You can also consider posting this question at the website/forum/mailinglist of the component manfacturer rather than here. At least I can tell you that the Sun JSF h:dataTable has the 'rows' attribute for that. I can also suggest you to just take a look in the TLD documentation of the component in question. There should be all possible attributes listed with a detailed explanation about the behaviour.
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Babu..Hello,
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How to display number of rows as columns in a select statement? This is on
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How to count number of rows in table
can I get number of row in table except Count(*) in pl/sql
is there any other wayAlso posted and answered here
how to count number of rows in table
count(*) will be the fastest way. It is only slow if the table has a vast number of rows, in which case why do you need to know the tables has 73552436467721 rows and not 73552436467737 rows. It doesn't seem to be much use. Either that or you are counting them a lot, which again seems rather pointless. -
How to increase number of rows display in ESS
Hi All,
how to increase number of rows display in ESS applications especially in Time approval inbox from standard display of 5 rows to say like 20 rows? is there a quick way to do it?
Thanks all
MurtyKalpesh,
it is actually in web dynpro view, I have seen this setting and it doesnt give option for increasing default number of rows in web dynpro application. Table is dynamically constructed in web dynpro implementation and I have the hard time finding out., Any help is appreciated in these lines,
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Murty -
How to restrict number of row/lines in a table in RTF
Hi,
Im working on PO report. It has header information in the header part of RTF. But coming to the lines , I put that under a different group in the table in the body part of the RTF. I did a FOR loop for printing PO Lines because it does have multiple line information. But now i have to restrict the number of rows in that table per page irrespective of number of PO Lines. After printing 20 rows in the table, it should go to the next page. Im going through the other threads for the solution.
Thanks,
venkatThere are so many thread regarding this ,
pls go thru them patiently...
logic is something like....
use if condition and position() and say page-break..
use for-each@section instead of for-each..so that the headed info is maintained with regards to PO lines
happy searching...
if you cant get still, last option send me mail with details -
Determine Number of rows in Internal Table
Hi,
I have defined my internal table as follows:
TYPES : BEGIN OF ABC_KEY,
FIELD1(2) TYPE C,
FIELD2(1) TYPE C,
FIELD3(8) TYPE N,
END OF ABC_KEY.
DATA: itab1 TYPE TABLE OF ABC_KEY
WITH KEY FIELD1,
wa_lines_1 LIKE LINE OF itab1.
How can I retrieve the number of rows in Internal Table?
Thanks.
Regards,
bw_newbieYou can define the number of rows of the internal table using the DESCRIBE itab command .
As the rest have already stated a sample code snippet .
For more info type in DESCRIBE in your prgram and click on (F1) by placing the cursor on DESCRIBE .
You will find more options as to how you can use the DESCRIBE command according to your requirement .
Thanks ,
Hari -
Displayin message and fixing the number of rows in a table
Hi Experts,
I have a requirement like this
there is a table, where i need to diplay a message when there are no records and no rows should be visible on that table.
Also, when the records are populated from the context, i need to fix the number of rows in that table and display the records.
Please let me know hw this can be achieved.
Also in the table I have Link to URL, please let me know how to handle this reference, when i set the reference Property, its giving me an error stating that the file doesn't exist when the table gets loaded.
Thanks in Advance
Regards,
PalaniHi
Oh!! You should to explain it at first thread itself that you want to display a JPG imange or other WDWebResourceTypetaken form the backend.
1. So this is not at all a URL
2. You have to convert binary data to WDWebResource then display it in either Image UI element or other (like PDF , txt etc)
3
try
// Read the datasource of the FileUpload
IWDResource res = wdContext.currentContextElement().getResource();
InputStream in = res.read(false);
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
int length;
byte[] part = new byte[10 * 1024];
while ((length = in.read(part)) != -1)
bOut.write(part, 0, length);
in.close();
bOut.close();
IPrivateUploadCompView.IImageTableElement ele = wdContext.nodeImageTable().createImageTableElement();
ele.setImage(wdContext.currentContextElement().getResource().getUrl(0));
ele.setText(res.getResourceName());
wdContext.nodeImageTable().addElement(ele);
catch (Exception e)
wdComponentAPI.getMessageManager().reportWarning(e.toString());
Here I assume that you convert that data to IWDResource type or
4.
WDWebResource.getWebResource(wdContext.currentContextElement().getresource(), type);
// getResource of type binary which u read from BAPI and set it in local context , type is MIMETYPE or hardcode it as "JPG"
5. Further help
[Help1|To Displayan Image in Webdynpro Java from Standard Function Module;
[Help2|http://wiki.sdn.sap.com/wiki/display/KMC/GettinganimagefromKMDocumentstobeusedinWeb+Dynpro]
[Help3|http://wiki.sdn.sap.com/wiki/display/KMC/GettinganimagefromKMDocumenttobeusedinWeb+DynPro]
It might code look strange at first , please do some reserch in SDN ,I did my best at this level.
Best Regards
Satish Kumar -
Hi
How to find the number of rows in each table of a database by just using a SQL query,
and should not use the data dictionary tables also... is there any way...??
Thanks
MJIt can be done in a single SQL like ->
satyaki>
satyaki>select * from v$version;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
Elapsed: 00:00:00.00
satyaki>
satyaki>
satyaki>SELECT table_name,
2 DBMS_XMLGEN.getxmltype ('SELECT Count(*) c FROM ' || table_name).EXTRACT ('//text()').ge
tnumberval() tot_rows
3 FROM user_tables;
TABLE_NAME TOT_ROWS
QUESTIONTYPE 0
SRGROUPTABLE 1
ST_TEST 4
REGISTER 0
DEB_1 2
EMP1 0
6 rows selected.
Elapsed: 00:00:12.04Credit goes to Michael. ;)
Regards.
Satyaki De. -
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