i am trying to get rows count of my table in my java project using jdbc connection to Hive database.
My code:
Statement s = con.createStatement();
ResultSet r = s.executeQuery("SELECT COUNT(*) AS rowcount FROM TABLE_NAME");
r.next();
int count = r.getInt("rowcount") ;
r.close() ;
System.out.println("MyTable has " + count + " row(s).");
When i start this function, my project freeze and nothing happens. I tried to debug, the result was: when program reach this place
ResultSet r = s.executeQuery("SELECT COUNT(*) AS rowcount FROM TABLE_NAME");
nothing happens and debuger shut down.
select * from TABLE_NAME
works fine, but counting rows from the same table doesnt work. Any ideas? :)
Related
Already checked this post: SSIS and sending query with date to Oracle
And I'm using variable query per below thread
SSIS - Using parameters in Oracle Query using Attunity Oracle Datasource
Tool used: VS-2019
Data flow: MS Oracle Source (for VS-2019)
My source is Snowflake cloud. I'm successfully able to get the max date from table and store in Object type variable (named:- #var_Snowflake_Table_maxDate). Then I use a script task to convert the value to string type.
Code for script task is:
public void Main()
{
OleDbDataAdapter A = new OleDbDataAdapter(); //using System.Data.OleDb; ADDED above in NAMESPACES
System.Data.DataTable dt = new System.Data.DataTable();
A.Fill(dt, Dts.Variables["User::var_Snowflake_Table_maxDate"].Value);
foreach (DataRow row in dt.Rows)
{
object[] array = row.ItemArray;
Dts.Variables["User::var_CreateDate"].Value = array[0].ToString();
}
Dts.TaskResult = (int)ScriptResults.Success;
}
This sets my param of #var_CreateDate String type correctly. I tried this on local machine and was able to pass the value to a native instance of sql-server(yes NOT oracle). Just to test my parameters from script task works.
Finally: I'm using VS-2019's MS Oracle Source to pass the value into Oracle cloud server. Sample query's I have tried
"select * from Table where rownum <= 5 and NVL(CREATE_DATE,UPDATE_DATE) = " +"'05-09-2020'"
::::evals to::::
select * from relate.awd_acct_activity where rownum <= 5 and NVL(CREATE_DATE,UPDATE_DATE) = '2020-05-09'
and this works. But value is hard coded.
Try 2:
"select * from table where rownum <= 50 and
NVL(CREATE_DATE,UPDATE_DATE) = " +"'#[User::var_CreateDate]'"
Try 3:
"select * from table where rownum <= 50 and
NVL(CREATE_DATE,UPDATE_DATE) = to_date(" +"'#[User::var_CreateDate]'"+")"
Try 4:
"select * from table where rownum <= 50 and
NVL(CREATE_DATE,UPDATE_DATE) = to_date(" +"'#[User::var_CreateDate]'"+",'YYYY-MM-DD')"
None of try 2 through 4 eval correctly. Can I have some guidance into how to pass this parameter to Oracle cloud.
Thanks.
I'm assuming you're trying to figure out the syntax for a variable, that would hold the query text. You can try something like this:
"select * from table where rownum <= 50 and
NVL(CREATE_DATE,UPDATE_DATE) = to_date(" + "'" + #[User::var_CreateDate] + "'" + ",'YYYY-MM-DD')"
I have the following query which correctly returns records when I execute it via code or Oracle SQL Developer.
SELECT TABLE_T.COL_P,
1234 AS COL_C,
TABLE_T.COL_D,
SUM(SOME_COLUMN) Value
FROM TABLE_T
INNER JOIN TABLE_E E ON TABLE_T.COL_P = E.COL_P
AND TABLE_T.COL_C = E.COL_C
AND TABLE_T.COL_CC = E.COL_CC
AND TABLE_T.COL_CL = E.COL_CL
INNER JOIN TABLE_C C1 ON C1.COL_P = E.COL_P
AND C1.COL_C = E.COL_C
INNER JOIN TABLE_C C2 ON C2.COL_P = C1.COL_P
AND C2.COL_CX = C1.COL_CX
AND C2.COL_CY = C1.COL_CY
AND C2.COL_CZ = C1.COL_CZ
WHERE TABLE_T.COL_P = 'Some Text'
AND C2.COL_C = 1234
AND TABLE_T.COL_CL IN
(SELECT COL_CL
FROM TABLE_CL
WHERE COL_P = 'Some Text'
AND ((COL_CLTYPE = 'VALUE_A')
OR (COL_CLTYPE = 'VALUE_B')
OR (COL_CLTYPE = 'VALUE_C')
OR (COL_CLTYPE = 'VALUE_D')) )
GROUP BY TABLE_T.COL_P,
TABLE_T.COL_D
However, it fails to return records once I execute the following session commands:
ALTER SESSION SET NLS_COMP = LINGUISTIC;
ALTER SESSION SET NLS_SORT = BINARY_CI;
This problem only occurs when I'm running against an Oracle 12c or 18c database.
It works find with/without the session commands when running against an Oracle 12C R2 or 11g database.
I've already checked the Explain Plan for 12c/18c and 12cR2 and its creating the same plan.
I found out that by adding an ORDER BY clause to the query (ORDER BY TABLE_T.COL_D, it resolves the problem.
Any ideas on what might be causing this problem?
I know the ORDER BY solution works, but I'd like to know what the underlying cause is and if there's a better solution to it.
i just created the trigger
here is the code:
CREATE OR REPLACE TRIGGER tr_update_solde_nbreserv
AFTER INSERT ON reservation
FOR EACH ROW
BEGIN
UPDATE CLIENTS
SET CLIENTS.NB_RESERV = NB_RESERV+1 , CLIENTS.SOLDE = SOLDE+1
FROM dbo.clients as c
INNER JOIN dbo.reservation as r
ON c.numc = r.numc
WHERE r.numr = :new.numr;
BEGIN
SELECT fillHist_station FROM DUAL;
END;
end tr_update_solde_nbreserv;
i'm getting these 2 errors:
Error(1,9): PL/SQL: SQL Statement ignored
Error(3,9): PL/SQL: ORA-00933: SQL command not properly ended
how can i fix them
There are several issues with your trigger code.
1) The purpose of this part of the code is unclear :
BEGIN
SELECT fillHist_station FROM DUAL;
END;
fillHist_station is not declared, hence this code would raise an invalid identifier error.
2) The syntax of the UPDATE query is invalid. Also, your intend is to select from the table that the trigger fired on, which is not allowed in Oracle. From looking at your code, it looks like you don't actually need to query RESERVATION to achieve your goal. As a row was just inserted in RESERVATION, you already know the corresponding client number.
3) You miss a / at the end
Here is an updated version of your code, that you can play around with in this db fiddle (you did not provide the structure of your tables so I just created the coulmns that are referenced in the query) :
CREATE OR REPLACE TRIGGER tr_update_solde_nbreserv
AFTER INSERT ON RESERVATION
FOR EACH ROW
BEGIN
UPDATE CLIENTS
SET NB_RESERV = NB_RESERV+1 , SOLDE = SOLDE+1
WHERE numc = :new.numc;
END tr_update_solde_nbreserv;
/
update CLIENTS
SET CLIENTS.NB_RESERV = NB_RESERV+1 , CLIENTS.SOLDE = SOLDE+1
FROM dbo.clients as c
inner join dbo.reservation as r
on c.numc = r.numc
where r.numr = :new.numr;
update with inner join is not supported in Oracle database in this way. furthermore dbo.clients and dbo.reservations look like Sql Server tables rather then oracle.
I believe that you are looking for something like this, but I am not sure about the relations. You may need to fix the query.
UPDATE
(
SELECT clients.nb_reserv, r.nb_reserv as r_nb_reserv, clients.solde, r.solde as r_solde
FROM clients
inner join reservation as r
on c.numc = r.numc
where r.numr = :new.numr
) t
SET CLIENTS.NB_RESERV = r_nb_reserv + 1, clients.solde = r_solde+1;
Simpler approach
UPDATE clients SET NB_RESERV = (SELECT nb_reserv +1
FROM reservations
WHERE c.numc = r.numc and r.numr = :new.numr),
SOLDE = (SELECT SOLDE +1
FROM reservations
WHERE c.numc = r.numc and r.numr = :new.numr)
WHERE EXISTS (SELECT 1 FROM reservations
WHERE c.numc = r.numc and r.numr = :new.numr);
I have a query that selects a single column and I am executing the query in batches using setFirstResults & setMaxResults methods of SQLQuery.
Snippet:
SQLQuery query = <query object with query projecting a single column>;
int maxResults = 50;
int batchSize = 50;
for (int i = 0; ; i++) {
query.setFirstResult(batchSize*i);
query.setMaxResults(maxResults);
List resultSet = query.list();
if(resultSet.isEmpty())
break;
//process result set
}
I set to true the showSQL parameter in hibernate config to see the query string that hibernate produces. For the first batch, i.e. when i=0 below is the query that hibernate generates:
select * from (/* query selecting single column here */) where rownum <= ?;
which makes sense since its the first batch and we want results from first row and rownum is used to restrict the number of results to maxResults.
Now for the second and subsequent batch reads, the query hibernate generates is:
select * from ( select row_.*, rownum rownum_ from (/*query selecting single column here */) row_ where rownum <= ?) where rownum_ > ?;
and you can clearly see, the above query is selecting two columns, one being the row number itself.
So when my query only selects one column, hibernate's version of the query is selecting two.
Is this known issue? Can I do something different or am I doing something wrong?
I don't want to cast the result set into two different types before using/processing it.
Ok, I know the answer is simple and I'm going to feel pretty dumb but...
Java JDK 1.7, Sybase JDBC driver
Code snipit:
String sql = "select <blah>
from <blah blah>
where date1 = ?
UNION
select <blah>
from <blah blah>
where date2 = ?";
Connection conn = ConnectionManager.getConnection();
PreparedStatement stmt = conn.prepareStatement(sql);
logger.info("parmemeter count: " + stmt.getParameterMetaData().getParameterCount());
stmt.setDate(1, new java.sql.Date(date.getTime()));
stmt.setDate(2, new java.sql.Date(date.getTime()));
ResultSet rs = stmt.executeQuery();
while rs.next()) {
// the rest of the code
}
So why is the parmeter count only 1?
Running the program throws an error complaining: java.sql.SQLException: Invalid parameter index 2.
If I reduce the sql to either piece and reduce the setDate() to only 1 it works just fine.
The SQL with the UNION runs just fine in an interactive sql session (? filled in with a date of course)
I just ran into this problem, and this thread was very helpful. It's not the union clause that's throwing errors; it's the date that you're passing in. If you're using to_date () (unclear from your code snippet), you need to be passing a string in the query (instead of a date). Good luck!