I have a big but INTERMITTENT problem with a bug in Oracle 10g when we call some SQL within a Java web application. We can't quickly patch or upgrade to 11g - which seems to be the first 'stupid' oracle support response. There is a work around, but I am having trouble doing this within PreparedStatements within my Java code.
The actual error is:
ORA-00600: internal error code, arguments: [kcblasm_1]
The bug is: Oracle Bug 12419392
The work around is running
alter session set "_hash_join_enabled" = FALSE;
before we run our bug-inducing SQL. However, traditionally a PreparedStatement takes in one single piece of SQL:
PreparedStatement stmt = con.prepareSelect("sql statement2");
Is it possible to have one PreparedStatement call that looks like this:
PreparedStatement stmt = con.prepareSelect("sql statement1; sql statement2;");
Or is this possible just by running a series of sequential PreparedStatements one after the other?
Not the best time to be getting this with Xmas looming and reduced support etc. etc., so I really hope someone can help. Thanks.
Edit: #jonearles asked for the code, so here it is, if it's on any use. Probably very specific to our project, but someone might spot the glaring bug-inducing issue:
SELECT DISTINCT qm.validator_id,
qm.QM_ID,
u.EMAIL,
qm.creation_dt,
qm.emailed,
qm.valid,
qm.resolved,
qm.new_obs_id,
o.*,
nests.*,
s.*,
l.*,
latc.TENKM
FROM query_man qm,
obs o,
obs_aux_aon nests,
sub s,
location l,
l_atlas_tetrad_coverage latc,
users u
WHERE qm.OBS_ID = o.OBS_ID
AND o.SUB_ID = s.SUB_ID
AND u.user_id = qm.user_id
AND o.obs_id = nests.obs_id(+)
AND s.LOC_ID = l.LOC_ID
AND latc.ATLAS_REGION = 'NKNE'
AND (LENGTH (l.gridref) = 6
AND (SUBSTR(l.gridref,1,3)
|| SUBSTR(l.gridref,5,1)) = latc.TENKM
OR LENGTH (l.gridref) = 4
AND l.gridref = latc.TENKM)
AND qm.RESOLVED IS NULL
ORDER BY latc.tenkm,
l.tetrad
OK. The answer to my primary question is NO, you can't create a PreparedStatement like so:
PreparedStatement stmt = con.prepareSelect("sql statement1; sql statement2;");
Running individual statements to alter session temporarily for one bit of SQL did work, but agreed seems awful and also unacceptably slowed response. Options seem to be patch or upgrade, or look into the no_use_hash hint (which I think will be slow too). Will look at code.
Related
Before I explain my problem I would like to say that I know the basics of JDBC but not really used to it.
I am using an updatable result set to hold data from 2 different tables, as in the following sample code:
searchQry = "SELECT ct.CustomerName, ct.Email, ct.PhoneNo, ot.ItemName
FROM CUSTOMER_TABLE ct JOIN ORDER_Table ot
ON ct.OrderID = ot.OrderID";
prestmt = dbcon.prepareStatement(searchQry, ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
uprs = prestmt.executeQuery();
uprs.updateLong("ut.PhoneNo", 7240987456L);
uprs.updateString("otItemName", "GTA5");
uprs.updateRow();
I would like to know if I will update the database from somewhere else (not using the same result set object) while the result set, upsr, connected to the database, whether uprs will get updated with it or it will throw an error or it will go with the old data itself. Sorry if it a newbie question but I can't really test that on my DB without knowing the outcomes and safe measures.
Please, suggest me if there is any better way to update the underlining db along with the data in the ResultSet without having any transaction issues when changing from different places.
Using:
Oracle Database for JDBC connection.
I have a wierd behavior in a Java application.
It issues simple queries and modifications to a remote MySQL database. I found that queries, run by executeQuery() work just fine, but inserts or delete to the database run through executeUpdate() will fail.
Ruling out the first thing that comes to mind: the user the app connects with has correct privilledges set up, as the same INSERT run from the same machine, but in DBeaver, will produce the desired modification.
Some code:
Connection creation
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager.getConnection(url, user, pass);
Problematic part:
Statement parentIdStatement = connection.createStatement();
String parentQuery = String.format(ProcessDAO.GET_PARENT_ID, parentName);
if (DEBUG_SQL) {
plugin.getLogger().log(Level.INFO, parentQuery);
}
ResultSet result = parentIdStatement.executeQuery(parentQuery);
result.first();
parentId = result.getInt(1);
if (DEBUG_SQL) {
plugin.getLogger().log(Level.INFO, parentId.toString()); // works, expected value
}
Statement createContainerStatement = connection.createStatement();
String containerQuery = String.format(ContainerDAO.CREATE_CONTAINER, parentId, myName);
if (DEBUG_SQL) {
plugin.getLogger().log(Level.INFO, containerQuery); // works when issued through DBeaver
}
createContainerStatement.executeUpdate(containerQuery); // does nothing
"DAOs":
ProcessDAO.GET_PARENT_ID = "SELECT id FROM mon_process WHERE proc_name = '%1$s'";
ContainerDAO.CREATE_CONTAINER = "INSERT INTO mon_container (cont_name, proc_id, cont_expiry, cont_size) VALUES ('%2$s', %1$d, CURRENT_TIMESTAMP(), NULL)";
I suspect this might have to do with my usage of Statement and Connection.
This being a lightweight lightly-used app, I went to simplicity, so no framework, and no specific isntructions regarding transactions or commits.
So, in the end, this code was just fine. It worked today.
To answer the question: where to look first in a similar case (SELECT works but UPDATE / INSERT / DELETE does not)
If rights are not the problem, then there is probably a lock on the table you try to modify. In my case, someone left with an uncommited transaction open.
Proper SQL exceptions logging (which was suboptimal in my case) will help you figure it out.
I'm having a problem I haven't encountered before: there is a stored function in a database: CC_PROC, which takes two date entries and returns a table. In other words, to call it, you type:
SELECT * FROM (TABLE( CC_PROC( DATE '2012-01-01', DATE '2012-01-15')));
This seems to work perfectly in SQLPlus and NetBeans, and the above line has been apparently been in use for some time.
Anyway, when calling it from java using a prepared statement, I get: "CC_PROC": invalid identifier on the executeQuery call.
This is with:
PreparedStatement preparedStatement =
connection.prepareStatement("SELECT * FROM (TABLE ( CC_PROC( ? , ? )))");
preparedStatement.setDate(1,firstDate);
preparedStatement.setDate(2,secondDate);
resultSet = preparedStatement.executeQuery();
I feel like maybe this is obvious and my limited experience using JDBC directly instead of Hibernate is throwing me. I'd like to not have to re-code the contents of CC_PROC in java business logic. Any ideas?
Thanks!
Aha, found the answer:
The oracle user was SALESOWN, so the fix was:
PreparedStatement preparedStatement = connection.prepareStatement(
"SELECT * FROM (TABLE ( SALESOWN.CC_PROC( ? , ? )))");
Yikes. I don't want to admit the amount of time it took to figure that out.
Apparently SQLPlus and NetBeans do attempt to help out a little...
Thanks for the help guys!
Is there any way to get the Oracle query from PreparedStatement .I know its not possible as such I can't use log4jdbc or p6spy as it is a secured application and using this will create bigger problems..toString won't work as I am using Oracle? I can't change PreparedStatement to Statement either.
If only need for debug time then You can use DebuggableStatement follow this article
I don't think you should be doing it this way, as there is no officially documented API for this.
If you can mess with the code, why cannot you use log4jdbc ?
Oracle JDBC also supports java.util.logging, which you could try to enable.
If you are just interested in the SQL itself, you can turn on session tracing on the Oracle server.
Or maybe you can put your code to where the statement is being prepared (using something like #pinichi is suggesting)?
But just for fun, poking around with the debugger, with my version of Oracle JDBC, I can do
if (stmt instanceof oracle.jdbc.driver.OraclePreparedStatement) {
String x = ((oracle.jdbc.driver.OraclePreparedStatement) stmt)
.getOriginalSql();
System.out.println(x);
}
If you just want to check SQL statement you can also go straight to the database and check v$sql table.
There you can find all sqls and other information about query. More info: http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/dynviews_2113.htm
Started coming up with a java web app for online user interaction. Decided to use a MySql DB for data storage. I have already created the tables with the proper/expected data types. My question is I always thought the next step would be to creat stored procedures like Search/Add/Delete/etc.. that the user could envoke from the page. So in my java code I could just call the procedure ex:
CallableStatement cs;
Try
{
String outParam = cs.getString(1); // OUT parameter
// Call a procedure with one in and out parameter
cs = connection.prepareCall("{call SearchIt(?)}");
cs.registerOutParameter(1, Types.VARCHAR);
cs.setString(1, "a string");
cs.execute();
outParam = cs.getString(1);
}
catch (SQLException e) {
}
but if my application was not in the need for stored procedures because the user actions would be simple enough to execute simple tedious queries. How could I set up my Java and Sql code to handle that. Could I just have the "Select" or "Update" statements in my code to manipulate the data in my MySQL DB. If so how would that syntax look like?
This URL has documentation on using prepared statements which is what you want to use to avoid security flaws (SQL Injection and such).
http://download.oracle.com/javase/tutorial/jdbc/basics/prepared.html
here's an example from that page
PreparedStatement updateSales = connection.prepareStatement(
"UPDATE COFFEES SET SALES = ? WHERE COF_NAME LIKE ? ");
updateSales.setInt(1, 75);
updateSales.setString(2, "Colombian");
updateSales.executeUpdate():
Just use Statement, or PreparedStatement.
http://download.oracle.com/javase/1.4.2/docs/api/java/sql/Statement.html
In a similar way to what you did, just call :
Statement stm = Connection.createStatement();
then execute your SQL :
stm.execute("SELECT * FROM MYTABLE");
grab the resultset and check out the results.
Beware though - this is bad bad as far as security goes - as others have mentioned, PreparedStatements are a bit more secure, but still not 100%.
To be honest, although basic JDBC is pretty simple, I really hate all the SQL strings littered around your code. If you want something a bit more elegant have a quick look at hibernate - it hides all the hackiness from you, and is also pretty easy to setup.