I have the piece of code displayed below. My challenge is that the code only works the second (third and so on) times it's submitted. I change nothing between the two submits but the first time doesn't do what it's supposed to. Both time I get a job# returned as if everything is fine.
The procedure 'execute_plan' is supposed to update some rows in a table and this is not done until the second submit.
I have tried monitoring the USER_LOGS table and can see no difference whatsoever between the first and second submit.
I have tried replacing the call to another schema with a simple update on a table in the executing users schema. This works the first time.
So the problem seems to be related to calling a procedure in another schema.
EDIT: I have also tried to manually add conn.commit();, I have added commits in the PL/SQL but all in vain :-(
The entire logic is called from a java rest service.
BasicDataSource bds = Util.getDatasource(nodeData);
String plsql = "declare x number; begin x := dlcm_agent.runner.execute_plan(" + nodeData.get("lcPlanId") + "); end;";
Connection conn = null;
JSONObject json = new JSONObject();
try {
conn = bds.getConnection();
CallableStatement stmt = conn.prepareCall("begin dbms_job.submit(?,?); end;");
stmt.setString(2, plsql);
stmt.registerOutParameter(1, Types.BIGINT);
stmt.execute();
json.put("success", true);
} catch (Exception e) {
json.put("success", false);
json.put("message", e.getMessage());
} finally {
if (conn != null) conn.close();
}
return json.toString();
This is driving me insane so if anyone has any input please let me know
First, it would be good to close stmt, that has been used.
Also, it's recommended to use executeUpdate for stmts that make some data manipulations.
And third, dbms_job.submit - just submit job to jobs queue. It does not execute it (you probably know it).
Turned out to be an unhandled race condition. I updated a table before the submitted job had completed which caused an error.
Thanks
Related
I am still quite new to the world of java. I am working on my second application which is a program that mass updates a time field in my company's SQL database. I am able to run queries through java, and store each query line in a resultset just fine. The thing is that each line of the result set is an update statement. I want to then run those resultset lines. However over and over I keep getting the "SQL command not properly ended" error message when I know full well these statements are formatted correctly and run just fine in TOAD for oracle. Can anyone help me understand whats going on here? I have also tried batching and continue to get the same error.
This is an example of one of the output lines of my query with table and field names changed.
Update sometable.somefield set COMPLETED_TS ='31-OCT-17 06.00.00.000000000 AM'Where eqact_id ='2559340';
Below you can see the end of my SQL string and my runScript2() method.
"\r\n" +
"\r\n" +
"where \"Center\" = S.CODE and S.TIMEZONE_ID = T.ID"; //This String is named SQL1
public void runScript2(){
try {
PreparedStatement statement0 = Connection1.conn.prepareStatement(SQL1);
ResultSet result0 = statement0.executeQuery();
Connection1.conn.setAutoCommit(false);
while(result0.next()) {
PreparedStatement statementq1=Connection1.conn.prepareStatement(result0.getString(1));
statementq1.executeUpdate();
}
Connection1.conn.commit();
}catch (SQLException e1) {
e1.printStackTrace();
}
}
Well I am angry and happy at the same time as I figured out that the issue was that my result0.getString(1) lines had a semicolon at the end of each and for some reason Java didn't like this. They run just fine without this.
Live and you learn I guess.
I'm starting with SQL and trying to mix it with Java app. I have table ZAMESTNANEC containing 6 rows.
When I issue the command delete from ZAMESTNANEC where ID = 7; in SQL it will delete in no time. A few milliseconds. But when I use this in my Java app, the app will freeze in processing. I waited for 4 minutes and nothing happened (and due to its working state I can't do anything else). Oh and the row wasn't deleted.
I read this topic about deleting but it didn't help me much. In fact it didn't help me at all.
oracle delete query taking too much time
I tried to debug it but it's frozen on this command. I don't understand why in SQL it works fine and in Java app it doesn't. Other commands like SELECT works fine.
JDBC here - http://pastebin.com/BRh06yc8
Code from button here
private void jButtonOdeberZamActionPerformed(java.awt.event.ActionEvent evt) {
try{
OracleConnector.setUpConnection("xxxxxxxx", 1521, "ee11",
"NAME", "PASSWORD");
conn = OracleConnector.getConnection();
stmt = conn.createStatement();
stmt.executeQuery("delete from ZAMESTNANEC where ID = 7");
} catch(SQLException ex){
System.out.println(ex);
}
executeQuery should be used for queries that are expected to return results. Try executeUpdate instead and see if that helps. It could be that your app is waiting to receive results which never come back. By Tom H
Thank you Tom.
I have a long piece of code in java which uses selenium webdriver and firefox to test my website. Pardon me if I can't reproduce it here. It has an infinite while loop to keep doing its function repeatedly. Thats what its supposed to do. Also, I don't use multi threading.
Sometimes, it gets stuck. I use a windows system and the code runs on command prompt. When it gets stuck, no errors or exceptions are thrown. Its something like "it hangs" (only the window in which the code runs hangs). Then I have to use CTRL + C . Sometimes it resumes working after that, other times it gets terminated and I restart it. It works fine but after some loops it "hangs" again. Also, I've noticed that its usually during the execution of one of the methods querying mysql database.
The code runs an infinite loop. Each time, it queries the mysql database, fetches a value(whose 'status' field is not 'done') from a particular table (one value in each loop) and proceeds with testing with this value.At the end of the loop, the table is updated (the column 'status' is set to 'done' for that value). When there are no new values having 'status' not equal to 'done' in that particular table, it should ideally display "NO NEW VALUE". However, after all the values have been used, it simply takes up the last used value (even though its status is updated to 'done' at the end of previous loop) and goes ahead. I then have to terminate the execution and run the code again. This time when the infinite loop begins, it queries the database and correctly displays "NO NEW VALUE", queries again, displays the message again and so on(which is what it should do)
I close the sql connection using con.close().
It appears that after running the loop for a few times, some resource is getting exhausted somewhere. But this is only a wild guess.
Can anyone suggest what the problem is and how do I fix it ?
Below is a relevant piece of code :
try{
String sql = "select something from somewhere where id = ? and is_deleted = '0';";
System.out.println("\n"+sql + "\n? = " + pID);
PreparedStatement selQuery1 = conn.prepareStatement(sql);
selQuery1.setString(1, pID);
ResultSet rs1 = selQuery1.executeQuery();
//Extract data from result set
while(rs1.next() && i1<6){
//do something
}//end while loop
String sql2 = "select something2 from somewhere2 where id = ? and is_deleted = '0';";
System.out.println("\n"+sql2 + "\n? = " + pjID);
PreparedStatement selQuery2 = conn.prepareStatement(sql2);
selQuery2.setString(1, pjID);
ResultSet rs2 = selQuery2.executeQuery();
//Extract data from result set
while(rs2.next() && i1<6){
//do something
}//end while loop
System.out.println("\nDone.");
conn.close();
}catch (SQLException e) {
flag=false;
}
Please note that no exceptions are thrown anywhere. The window in which the code is running just freezes (that too once in while) after displaying both the query statements.
I forgot to close the query and the resultset. Just closing the connection should implicitly close the query and resultset but it doesn't work always.
I also faced the same problem recently. But in my case the issue was with indexes. I am just pointing out here so that it can be helpful to other folks.
In my case I am fetching the menu items from MenuMaster table from database. So after successfully log in, I am hitting a database to fetch the menu items using MySQL connector driver. Here I need to fetch parent menu with their child menus. In my query, in where clause I have not used any primary key or Unique key. So, it was taking a long time. So just make an index of that key, and it worked as charm...
I'm developing a web application with Play 2.1.0 and programming it with Java and I need to have access to data already saved in a DB to modify them.
I tried to create a new instance without the new operator and reference it to my object saved in the database, but even if there is no pointer error, it won't change values of attributes. I couldn't figure out why, so I've decided to enter SQL queries directly.
Same thing, it does not seems to have any mistake, but it won't change anything... I think this comes from a bad link to the database :
Here is my code in application.java :
public static Result modifyQuestionnaire(Long id) throws SQLException {
Statement stmt = null;
Connection con = DB.getConnection();
try {
stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
String query = "SELECT * FROM WOQ.questionnaire WHERE id=id";
ResultSet uprs = stmt.executeQuery(query);
uprs.updateString("name", "baba");
uprs.updateRow();
} catch(Exception e) {
e.printStackTrace();
} finally {
if (stmt!=null) {
stmt.close();
}
}
return redirect(routes.Application.questionnaire(id));
}
And I also try to enter an UPDATE query directly, still the same..
I've looked everywhere and did not find any solution (except Anorm but it seems to work with Scala language)
Btw, if anyone knows a solution with a second instance that refers to the same object (it seems possible but as I say, there is no error but no actions neither), it's fine for me.
Huh, you showed as that you are trying to create totally new connection, so I supposed, that you don't want to use Ebean, but in case when you are already use it, you can just use its methods for the task:
(copied) There are some options in Ebean's API, so you should check it and choose one:
Update<T> - check in the sample for #NamedUpdates annotation
Ebean.createUpdate(beanType, updStatement)
SqlUpdate - you can just perform raw SQL update, without need for giving the entity type
I have a problem and need some enlightenment here..
I am using trigger to detect change made to my database, means that I set all my table with trigger for insert, update, and delete (MySQL)
Then I write that change into a table that I have made specifically to contain all information about the change. Let's name it xtable. (This table is not equipped with trigger)
My Java program need to continuously read that xtable to let other application know about the change.
Well the problem is, when I read the xtable in a loop, I can only read the initial value of the xtable that is when I established the connection to the database. (connection is established outside the loop)
If a change has been made to the database which will lead to new row in xtable, this new row which is produced by the trigger is not detected no matter how many times I read it with executing "select * from xtable" query..
The code look like this:
public static void main(String[] args) {
Connection conn = null;
try {
conn = database.getConnection();
Statement state = conn.createStatement();
String query = "select * from `xtable`;";
while (true) {
ResultSet rs = state.executeQuery(query);
while(rs.next){
// Some code for letting the other application know of the change
}
}
} catch (SQLException ex) {
} finally {
if (conn != null) {
conn.close();
}
}
}
So basically if I run the program while the xtable is empty, I always gain an empty ResultSet even when there is a new row after sometimes.
Actually this problem can be solved by established the connection inside the loop, but then it will lead to another problem because it will consume more and more resource as the loop go around. (I have already try this and it will eventually use all resource on my computer after sometimes even when I have already properly closed it)
So can anyone please give me some suggestion what to do?
This is my first time posting a question here, I am sorry if there is some rule that I don't follow and please give me the right direction.
Thereis such thing as transaction isolation. It could be possible that your connection does not see changes because you did not commited transaction coming from trigger, or you did not started new one on client side. Impossible to tell without seeing your database set up.
PS: Message queuing is way better alternative
I think you'd better consider trigger instead of querying to the DBMS by looping.
If you use trigger you don't have to use that 'while' loop from Java side to check the change of DB.
Instead, trigger mechanism which is embedded in the DBMS will notify the Java side when the change happens.
For Oracle, you can call Java method from PL/SQL.
For PostgreSQL, you can call Java method from PL/Java.
For CUBRID, you can call Java method from Java stored procedure.
For MySQL, you can call Java method but I don't think it is as easy as above.
I wish this link would help you out. http://code.rocksol.it/call-java-from-mysql-trigger
Or google this keyword, "mysql java user defined functions"
Connection connection=getConnection();
statement="query";
try {
stmt = connection.prepareStatement(statement);
ResultSet rs = stmt.executeQuery();
while (rs.next()) {
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
if (connection != null && stmt != null) {
stmt.close();
}
}