Disadvantage of PreparedStatement

I dont see how a sequence can be used with prepared statement...
If I want to set pstmt.setInt(1,sequence.nextval) ?? This cant be done without creating another query to check the nextval of the sequence...
In a normal Statement I can do this....
INSERT INTO suppliers
(supplier_id, supplier_name)
VALUES
(supplier_seq.nextval, 'Kraft Foods');
Is there a way that I am not aware of of doing sequences and PreparedStatements without additional querying ?

pstmt.setString(myseq); ?No that is wrong.
it would be the equivalent of
INSERT INTO suppliers
(supplier_id, supplier_name)
VALUES
('supplier_seq.nextval', 'Kraft Foods'); Is there any reason you can't just do this?
INSERT INTO suppliers
(supplier_id, supplier_name)
VALUES
(supplier_seq.nextval, ?); Every time you execute the prepared statement it will call supplier_seq.nextVal, and assign a new id. Exactly as it would for a plain statement
Preparing the query doesn't actually run the nextval. That happens when every time you execute.
Cheers,
evnafets

Similar Messages

Oracle, SELECT IN and PreparedStatement.setArray

I want to execute the following query: SELECT * FROM SOMETABLE WHERE IDFIELD IN (?)
The number of values in the IN list is variable. How can I do this with a prepared statement?
I am aware of the different alternatives:
1) Keep a cache of prepared statement for each sized list seen so far.
2) Keep a cache of prepared statements for different sizes (1, 5, 10, 20) and fill in the left over parameter positions with the copies first value.
They both have the disadvantage that there could be many prepared statements for each query that get used once, and never used again.
I have tried this:
stmt.execute ("CREATE OR REPLACE TYPE LONGINTLIST AS TABLE OF NUMBER(15)");
ArrayDescriptor desc = ArrayDescriptor.createDescriptor ("LONGINTLIST", conn);
long idValues [] = {2, 3, 4};
oracle.sql.ARRAY paramArray = new oracle.sql.ARRAY (desc, conn, idValues);
PreparedStatement query = conn.prepareStatement ("SELECT * FROM MYTABLE WHERE ID_FIELD IN (?)");
query.setArray (1, paramArray);
But Oracle gives a data conversion error.
I then tried this:
PreparedStatement query = conn.prepareStatement ("SELECT * FROM MYTABLE WHERE ID_FIELD IN (SELECT * FROM TABLE (?))");
This works and the rows are returned, but the Oracle optimizer does not like it very much, since it always does a full table scan even though there is a primary key index on ID_FIELD.
Any ideas?
I also tried this:
OraclePreparedStatement oraQuery = (OraclePreparedStatement) query;
oraQuery.setARRAY (1, paramArray);
But same behavior.
Roger Hernandez

Please re-read the original message. As I mentioned,
I am aware of the two commonly used alternatives.No actually the most used alternative is to build the SQL dynamically each time.
I know how to get both of them to work, and have used
both alternatives in the past. The downside to both
these approaches is that you need to save multiple
prepared statements for each query. What I am trying
to find is a way of having only one saved prepared
statement for a query having a variable number of IN
clause parameters.You could probably use a stored procedure that takes an 'array' and then do the processing in the stored proc to handle each array element.
However, your database might not support that stored procs or arrays. Or it might not cache it with arrays. And the overhead of creating the array structure or processing it in the proc might eat any savings that you might gain (even presuming there is any savings) by using a prepared statement in the first place. Of course given that you must be using an automated profiling tool and have a loaded test environment you should be able to easily determine if this method saves time or not.
Other than that there are no other solutions.

Disadvantages in prepared statement

hi
i could not tell the answer for the following question in my interview can u pleae tell me the answer for this question
one of the disadvantages with prepared statement in jdbc?

I have no idea what WorkForFood is talking about.Sorry, perhaps an example will help clarify:
Using a PreparedStatement using two replacement parameters:
String sql = "SELECT COL1 FROM MYTABLE WHERE COL1 = ? AND COL2 = ?";
ps.setSetring("WORK");
ps.setString("FORFOOD");Contrasted against a Statement using literals:
"SELECT COL1 FROM MYTABLE WHERE COL1 = 'WORK' AND COL2 = 'FORFOOD'";When you execute these two queries, they can generate different explain plans, for example the Statement may use an index while the PreparedStatement may attempt a full table scan. The optimizer is choosing a more efficient explain plan for the Statement because it has more information on which to make a decision (the literal values). A full table scan will be significantly slower then using an index to return the same results. In some databases, you can provide hints, but in some cases, the only way to get this query to use an index is to provide the actual values WORK and FORFOOD in the query itself. When using literals rather then replacement parameters it should be more efficient to use Statement then PreparedStatement (see jschell's list #1). So, in these cases, you should use a Statement rather then a PreparedStatement to get best performance from your query. And again, this issue comes up very infrequently but can be quite debilitating to an applications performance when it does occur.

Disadvantages of using REFCURSORs from JDBC

Hi,
Normally I write my SQL statements from inside Java (eg PreparedStatements).
I am investigating on creating PL/SQL Packages, supplying procedures and methods, which I can call from Java using CallableStatements. I understand the advantages of having a layer/API on the database side.
For example: retrieve some records from a table. (the PL/SQL function getCustomers returns a REFCURSOR)
- PreparedStatement (select ... from ... where ...) -> executeQuery -> loop ResultSet
- CallableStatement ("begin ? := getCustomers(); end;") -> cast getObject() to ResultSet -> loop ResultSet
What are the disadvantages of using the CallableStatement (REFCURSOR)?
Thanks, regards, Stephan

While that article may be a good intro for someone not familiar with JDBC it has some misinformation in it that can be misleading at best and cause performance and memory issues at worst.
Row-prefetching - there is little benefit to using a large value for this setting. As with most things extremes are to be avoided.
It is important to know how the data is going to be used. What is the point of bringing ALL the data from the DB in one call if you are going to write it to the file system. File I/O is generally the slowest part of an application.
It is also important that the code be scaleable. Apps should be written so that future modifications will impact existing functionality as little as possible. If you eat up the memory for one table or statement that limits the memory available for other uses. Worse, when things go wrong and you need to reduce the fetch setting you may now have problems everywhere because the testing you originally performed may have relied on that larger fetch setting.
If the data fetching is not done in its own thread then using a very large value can actually make an application appear to 'freeze' while it waits for the data fetch to complete.
A large fetch size can also waste significant amounts of memory; essentially allocating it but never using it and never allowing any other process to use it. This is because for a fetch size of 'n' Oracle has to allocate space for 'n' rows that are each of maximum size.
This wasted is most often due to the common VARCHAR2 datatype. Consider a single column defined as VARCHAR2(100). In the DB this column is stored as variable length. But Oracle will allocate 100 characters (could be multi-byte characters) in order to be able to hold a maximum length value.
If the actual data values never exceed 30 bytes then 70 bytes in each row are totally wasted. The more rows that are prefetched the more memory that is wasted simply in anticipation of a maximum length value that never occurs or only occurs rarely.
I've never used a prefetch/fetch size greater than one thousand and that was for tables with small records (no more than 10 or 20 columns).
And the Oracle docs don't even recommend a setting that high. See the JDBC Dev Guide
http://docs.oracle.com/cd/B19306_01/java.102/b14355/oraperf.htm#i1043756
>
Oracle Row-Prefetching Limitations
There is no maximum prefetch setting, but empirical evidence suggests that 10 is effective. Oracle has never observed a performance benefit to setting prefetch higher than 50. If you do not set the default row-prefetch value for a connection, then 10 is the default.

How to print Integrity sql in the preparedstatement?

How to print Integrity sql in the preparedstatement?
Connection conn = null;
String sql = "select * from person where name=?";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setObject(1, "robin");
ps.executeQuery();
i'm wants print Integrity sql.
For example:select * from person where name='robin'
How should I do?
thanks a lot!

PreparedStatement doesn't offer methods for that. You can write your own implementation of PreparedStatement which wraps the originating PreparedStatement and saves the set* values and writes it to the toString().
If needed, myself I just print the sql as well as the values-being-set to the debug statement.Logger.debug(query + " " + values);

PreparedStatement not working

Hi,
I am having some problem using PreparedStatement.executeUpdate() . I want to be able to prepare several queries before commiting and I wrote this just to test it
PreparedStatement stmt= aConnection.prepareStatement("update trans_test1 set field1='a text field' where field1='other text'");
          stmt.executeUpdate();
          aConnection.commit();
          stmt.close();
          aConnection.close();
when it hits this line "stmt.executeUpdate();" the program just stops running and after a while throws this error.
java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction
I set the auto commit to false but I still can't get it working and do not understand the problem. Any one can help?
Thanks so much
Alejo

Hi,
I am having some problem using
PreparedStatement.executeUpdate() . I want to be able
to prepare several queries before commiting and I
wrote this just to test it
PreparedStatement stmt=
aConnection.prepareStatement("update trans_test1 set
field1='a text field' where field1='other text'");
          stmt.executeUpdate();This is wrong in so many ways:
(1) Use the bind variables.
(2) Close resources properly in a finally block.
(3) You don't show where you set auto commit to false
(4) You don't show where you rollback in the event of a failure.
>
I set the auto commit to false but I still can't get
it working and do not understand the problem. Any one
can help?A snippet like this isn't enough. Post all the code.
Which database are you using, and which driver?
%

Problem with PreparedStatement

I'm using a statement which needs to determine if the value is in a group.
The statement will be
"select name,age,occupation from personnel where age in ?"
ps.setString(1, "(20,21,22)");
I've also tried
ps.setString(1, "('20','21','22')");
Neither brings back any values in the result set.
I can't figure out how to print what the preparedstatement looks like after setting the value.
I look in the table and there are records with age 20, 21, 22.. and age is set as a string.

Try this:
    query_B = "select tablename.blah_blah_blah"
            + " from tablename"
            + " where tablename.etc is null"
            + "   and table.blah_term_code       in (?, ?)"
            + " order by 1, 2, 4, 7";
      String[] in_sem_dt = { "200307", "200308" };
      pstmt_B = con.prepareStatement( query_B );
      pstmt_B.setString( 1, in_sem_dt[0] );
      pstmt_B.setString( 2, in_sem_dt[1] );
      rs_B = pstmt_B.executeQuery();~Bill

Closing PreparedStatements & ResultSets

Is it necessary to explicitly close ResultSet AND PreparedStatement objects when used together? For example:
PreparedStatement ps;
ResultSet rs;
String sql = " SELECT * FROM some_table WHERE id = ? ";
try {
    ps = connection.prepareStatement(sql);
    ps.setString(1, someId);
    rs = ps.executeQuery();
    // And so on.....
} finally {
rs.close();
ps.close();
}Is it sufficient to close only the PreparedStatement? Does the ResultSet get cleaned up automatically when the PreparedStatement is closed? I don't want any lingering cursors left open, but at the same time, I don't want to write code that isn't needed. What's considered best form?
Thanks.
BTW: I'm using Oracle 8i/9i.

I always close a Statement object, but don't worry about the ResultSet...that's really just a matter of redundancy...
From the API on Statement.close()
Note: A Statement object is automatically closed when it is garbage collected. When a Statement object is closed, its current ResultSet object, if one exists, is also closed.

Too many connections - even after closing ResultSets and PreparedStatements

I'm getting a "Too many connections" error with MySQL when I run my Java program.
2007-08-06 15:07:26,650 main/CLIRuntime [FATAL]: Too many connections
com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: Too many connections
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:921)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2870)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:812)
        at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3269)
        at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1182)
        at com.mysql.jdbc.Connection.createNewIO(Connection.java:2670)I researched on this and found out that I wasn't closing the ResultSet and the PreparedStatement.
The JDBC connection is closed by a central program that handles connections (custom connection pooling).
I added the code to close all ResultSets and PreparedStatements, and re-started MySQL as per the instructions here
but still get "Too many connections" error.
A few other things come to mind, as to what I may be doing wrong, so I have a few questions:
1) A few PreparedStatements are created in one method, and they are used in a 2nd method and closed in the 2nd method
does this cause "Too many connections" error?
2) I have 2 different ResultSets, in nested while loops where the outer loop iterates over the first ResultSet and
the inner loop iterates over the second ResultSet.
I have a try-finally block that wraps the inner while loop, and I'm closing the second ResultSet and PreparedStement
in the inner while loop.
I also have a try-finally block that wraps the outer while loop, and I'm closing the first ResulSet and PreparedStatement
in the outer while loop as soon as the inner while loop completes.
So, in the above case the outer while loop's ResultSet and PreparedStatements remain open until the inner while loop completes.
Does the above cause "Too many connections" error?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The following is relevant sections of my code ( it is partially pseudo-code ) that shows the above 2 cases:
init( Connection jdbcConnection ){
   String firstSQLStatement = "....";
   PreparedStatement ps1 = jdbcConnection.prepareStatement( firstSQLStatement );
   String secondSQLStatement = "....";
   PreparedStatement ps2 = jdbcConnection.prepareStatement( secondSQLStatement );
   String thirdSQLStatement = "....";
   PreparedStatement ps3 = null;
   ResultSet rsA = null;
   try{
        ps3 = jdbcConnection.prepareStatement( thirdSQLStatement );
        rsA = ps3.executeQuery();
        if( rsA.next() ){
               rsA.getString( 1 );
   }finally{
        if( rsA != null )
               rsA.close();
        if( ps3 != null )
          ps3.close();
   //Notice, how ps1 and ps2 are created here but not used immediately, but only ps3 is
   //used immediately.
   //ps1 and ps2 are used in another method.
run( Connection jdbcConnection ){
     ResultSet rs1 = ps1.executeQuery();
        try{
           while(rs1.next()){
                String s = rs1.getString();
                ps2.setString(1, s);
          ResultSet rs2 = ps2.executeQuery();
                try{
               while(rs2.next()){
                    String s2 = rs2.getString();
                }finally{
               if( rs2 != null )
                 rs2.close();
               if( ps2 != null )
                 ps2.close();
     }catch( Exception e ){
          e.printStackTrace();
     }finally{
        if( rs1 != null )
              rs1.close();
           if( ps1 != null )
              ps1.close();
//Notice in the above case rs1 and ps1 are closed only after the inner
//while loop completes.
}I appreciate any help.

Thanks for your reply.
I will look at the central connection pooling mechanism ( which was written by someone else) , but that is being used by many other Java programs others have written.
They are not getting this error.
An addendum to my previous note, I followed the instructions here.
http://dev.mysql.com/doc/refman/5.0/en/too-many-connections.html
There's probably something else in my code that is not closing the connection.
But I just wanted to rule out the fact that opening a PreparedStatement in one method and closing it in another is not a problem.
Or, if nested ResultSet loops don't cause the problem.
I've read in a few threads taht "Too many connections" can occur for unclosed RS and PS , and not just JDBC connections.

Memory problems with PreparedStatements

Driver: 9.0.1 JDBC Thin
I am having memory problems using "PreparedStatement" via jdbc.
After profiling our application, we found that a large number oracle.jdbc.ttc7.TTCItem objects were being created, but not released, even though we were "closing" the ResultSets of a prepared statements.
Tracing through the application, it appears that most of these TTCItem objects are created when the statement is executed (not when prepared), therefore I would have assumed that they would be released when the ResultSet is close, but this does not seem to be the case.
We tend to have a large number of PreparedStatement objects in use (over 100, most with closed ResultSets) and find that our application is using huge amounts of memory when compared to using the same code, but closing the PreparedStatement at the same time as closing the ResultSet.
Has anyone else found similar problems? If so, does anyone have a work-around or know if this is something that Oracle is looking at fixing?
Thanks
Bruce Crosgrove

From your mail, it is not very clear:
a) whether your session is an HTTPSession or an application defined
session.
b) What is meant by saying: JSP/Servlet is growing.
However, some pointers:
a) Are there any timeouts associated with session.
b) Try to profile your code to see what is causing the memory leak.
c) Are there references to stale data in your application code.
Marilla Bax wrote:
hi,
we have some memory - problems with the WebLogic Application Server
4.5.1 on Sun Solaris
In our Customer Projects we are working with EJB's. for each customer
transaction we create a session to the weblogic application server.
now there are some urgent problems with the java process on the server.
for each session there were allocated 200 - 500 kb memory, within a day
the JSP process on our server is growing for each session and don't
reallocate the reserved memory for the old session. as a work around we
now restart the server every night.
How can we solve this problem ?? Is it a problem with the operating
system or the application server or the EJB's ?? Do you have problems
like this before ?
greetings from germany,

PreparedStatement ResultSet wrapper to auto close cursor

Hi !
Is it possible to create wrapper that will automatically close result set and prepared statements ?
I am sick of closing resultsets and preparedstatements in all my dao objects. Its all about neverending try catch and close code lines, it is all against the java garbage collector idea.
Do you have any workaround ? Or I need to use with those try catch and close.
Thanks !

when u allocate object u dont need to call free nor destory when u dont need the object anymore.
on the other hand, you need to call .close() when u dont need the prepared statement anymore

Setting a null(empty) binary stream in a PreparedStatement

How can I bind a null binary stream into a PreparedStatement?
In the following, if pMap is null how do I bind it? If I try to serialize a null pMap I get and error that not all columns bound.
if(pMap == null)
else
byte[] _bytes = SerializeUtility.serializeObject(pMap);
pStatement.setBinaryStream(pColCount, new ByteArrayInputStream(_bytes), _bytes.length);
Thanks,
David

I was too close to the monitor, couldn't see the big picture ! :-) Now it works.
Although, I still get that Websphere error:
7c7fc721 SharedPool I J2CA0086W: Shareable connection MCWrapper id 31c73d Managed connection comm.ibm.ws.rsadapter.spi.WSRdbManagedConnectionImpl@2e55c73d State:STATE_TRAN_WRAPPER_INUSE from resource jdbc/ds was used within a local transaction containment boundary.
It use to work fine, no errors.
Any ideeas??
mihut

PreparedStatement and empty String instead of space

Hi all, I would test a space value in a varchar field, i.e.:
PreparedStatement ps=con.prepareStatement();
String qry = "select a from table where b=? and c=?";
ps.setString(1,"value");
ps.setString(2," "); // space!!
That source code doesn't work: it set "" (empty String) in the second field, not " " (space).
Can I use PrepareStatement in any way to do this or I have to use only Statement?
Thanks.
Bye.

my friend, the question was: how do you know the
parameter is set to "" (empty string)?I don't know: I suppose!!! because it's the only reason for that it returns no record. I tested my query in this three ways:
1) directly in sqlplus: SELECT OCCFASE As fase, OCLCVVC as convRat, SUM(QTA1) As qta1UM, SUM(QTA2) As qta2UM
FROM DJITMPRE WHERE OCCFASE IN ('I','P') AND OCCCOSC='XXXXX' AND OCCITEM='RUG-02' AND OCCTPVR = 'RUG'
AND OCCVAR1 = '01' AND OCCVAR2 = 'WW' AND OCCVAR3 = '12' AND OCCTPIM = '01' AND MAGAZZINO = 'MAG03'
AND COMMESSA = ' ' AND ORIG = ' ' AND PARTITA = ' ' AND CONFIG = 0.0 AND VANO = ' '
GROUP BY OCCFASE, OCLCVVC
and it returns one record.
2) using Statement:
     Statement s = conn.createStatement();
     String societa=session.getCompanyLogisticName(DSession.TABLE_LOGISTIC);
          StringBuffer qry=new StringBuffer();
          StringBuffer whereClause=new StringBuffer();
          qry.append("SELECT OCCFASE As fase, OCLCVVC as convRat, SUM(QTA1) As qta1UM, SUM(QTA2) As qta2UM ");
          qry.append("FROM DJITMPRE ");
          qry.append("WHERE OCCFASE IN ('I','P') ");
          qry.append("AND OCCCOSC='");
          qry.append(societa);
          qry.append("' ");
          whereClause.append("AND OCCITEM='");
          whereClause.append(b.getItemCode());
          whereClause.append("' ");
          whereClause.append("AND OCCTPVR = '");
     if (b.getVariantType().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getVariantType(), 1));
     }else{
          whereClause.append(b.getVariantType());
     whereClause.append("' ");
     whereClause.append("AND OCCVAR1 = '");
     if (b.getFirstVariant().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getFirstVariant(), 1));
     }else{
          whereClause.append(b.getFirstVariant());
     whereClause.append("' ");
     whereClause.append("AND OCCVAR2 = '");
     if (b.getSecondVariant().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getSecondVariant(), 1));
     }else{
          whereClause.append(b.getSecondVariant());
     whereClause.append("' ");
     whereClause.append("AND OCCVAR3 = '");
     if (b.getThirdVariant().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getThirdVariant(), 1));
     }else{
          whereClause.append(b.getThirdVariant());
     whereClause.append("' ");
     whereClause.append("AND OCCTPIM = '");
     if (b.getPackingType().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getPackingType(), 1));
     }else{
          whereClause.append(b.getPackingType());
     whereClause.append("' ");
     whereClause.append("AND MAGAZZINO = '");
     if (b.getWarehouseCode().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getWarehouseCode(), 1));
     }else{
          whereClause.append(b.getWarehouseCode());
     whereClause.append("' ");
     whereClause.append("AND COMMESSA = '");
     if (b.getProjectItem().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getProjectItem(), 1));
     }else{
          whereClause.append(b.getProjectItem());
     whereClause.append("' ");
     whereClause.append("AND ORIG = '");
     if (b.getSourceLot().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getSourceLot(), 1));
     }else{
          whereClause.append(b.getSourceLot());
     whereClause.append("' ");
     whereClause.append("AND PARTITA = '");
     if (b.getLotNumber().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getLotNumber(), 1));
     }else{
          whereClause.append(b.getLotNumber());
     whereClause.append("' ");
     whereClause.append("AND CONFIG = ");
     whereClause.append(b.getItemConfiguration());
     whereClause.append("AND VANO = '");
     if (b.getLocation().equals("")){
          whereClause.append(EscapeString.getLengthString(b.getLocation(), 1));
     }else{
          whereClause.append(b.getLocation());
     whereClause.append("' ");
     qry.append(whereClause.toString());
     qry.append(" GROUP BY OCCFASE, OCLCVVC");
ResultSet rs = s.executeQuery(qry.toString());
and it returns one record.
3) using PreparedStatement:
StringBuffer qry=new StringBuffer();
qry.append("SELECT OCCFASE As fase, OCLCVVC as convRat, SUM(QTA1) As qta1UM, SUM(QTA2) As qta2UM ");
               qry.append("FROM DJITMPRE WHERE OCCFASE IN ('I','P') ");
               qry.append("AND OCCCOSC='").append(societa).append("' ");
               qry.append("AND OCCITEM=? AND OCCTPVR = ? ");
          qry.append("AND OCCVAR1 = ? AND OCCVAR2 = ? AND OCCVAR3 = ? ");
          qry.append("AND OCCTPIM = ? AND MAGAZZINO = ? AND COMMESSA = ? ");
          qry.append("AND ORIG = ? AND PARTITA = ? AND CONFIG = ? ");
          qry.append("AND VANO = ? ");
          qry.append("GROUP BY OCCFASE, OCLCVVC");
PreparedStatement bookedQtyPS = conn.prepareStatement(qry.toString());
bookedQtyPS.setString(1,b.getItemCode());
     if (b.getVariantType().equals("")){
          bookedQtyPS.setString(2,EscapeString.getLengthString(b.getVariantType(), 1));
     }else{
          bookedQtyPS.setString(2,b.getVariantType());
     if (b.getFirstVariant().equals("")){
          bookedQtyPS.setString(3,EscapeString.getLengthString(b.getFirstVariant(), 1));
     }else{
          bookedQtyPS.setString(3,b.getFirstVariant());
     if (b.getSecondVariant().equals("")){
          bookedQtyPS.setString(4,EscapeString.getLengthString(b.getSecondVariant(), 1));
     }else{
          bookedQtyPS.setString(4,b.getSecondVariant());
     if (b.getThirdVariant().equals("")){
          bookedQtyPS.setString(5,EscapeString.getLengthString(b.getThirdVariant(), 1));
     }else{
          bookedQtyPS.setString(5,b.getThirdVariant());
     if (b.getPackingType().equals("")){
          bookedQtyPS.setString(6,EscapeString.getLengthString(b.getPackingType(), 1));
     }else{
          bookedQtyPS.setString(6,b.getPackingType());
     if (b.getWarehouseCode().equals("")){
          bookedQtyPS.setString(7,EscapeString.getLengthString(b.getWarehouseCode(), 1));
     }else{
          bookedQtyPS.setString(7,b.getWarehouseCode());
//cat.debug("b.getProjectItem(): "+b.getProjectItem());
     if (b.getProjectItem().equals("")){
          //cat.debug("entro in 1 b.getProjectItem().length: "+b.getProjectItem().length());
          bookedQtyPS.setString(8,EscapeString.getLengthString(b.getProjectItem(), 1));
          //bookedQtyPS.setString(8," ");
     }else{
          //cat.debug("entro in 2 b.getProjectItem().length: "+b.getProjectItem().length());
          bookedQtyPS.setString(8,b.getProjectItem());
     bookedQtyPS.setString(8," ");
//cat.debug("b.getSourceLot(): "+b.getSourceLot());
     if (b.getSourceLot().equals("")){
          bookedQtyPS.setString(9,EscapeString.getLengthString(b.getSourceLot(), 1));
     }else{
          bookedQtyPS.setString(9,b.getSourceLot());
     bookedQtyPS.setString(9," ");
//cat.debug("b.getLotNumber(): "+b.getLotNumber());
     if (b.getLotNumber().equals("")){
          bookedQtyPS.setString(10,EscapeString.getLengthString(b.getLotNumber(), 1));
     }else{
          bookedQtyPS.setString(10,b.getLotNumber());
     bookedQtyPS.setString(10," ");
//cat.debug("b.getItemConfiguration(): "+b.getItemConfiguration());
     bookedQtyPS.setString(11,""+b.getItemConfiguration());
//cat.debug("b.getLocation(): "+b.getLocation());
     if (b.getLocation().equals("")){
          bookedQtyPS.setString(12,EscapeString.getLengthString(b.getLocation(), 1));
     }else{
          bookedQtyPS.setString(12,b.getLocation());
     bookedQtyPS.setString(12," ");
ResultSet rs = bookedQtyPS.executeQuery();
and it returns 0 records.
I hope I explained it well.

PreparedStatement space and empty String

Hi, I have this problem:
PreparedStatement bookedQtyPS = null;
String qry="SELECT * from djwsearch where djwitem=?;
bookedQtyPS = conn.prepareStatement(qry);
if(item.equals(""){ //item is an empty String
bookedQtyPS.setString(1," "); // I set space instead of empty String
}else{
bookedQtyPS.setString(1,item);
My problem is that I need to set space insteadOf empty String, but I think that I can not use PreparedStatement to do this. I have performance problems (my query is much more complicated than this one) so I choose PreparedStatement and not Statement.
How can I do? Is this bug solved using PreparedStatement?
Thanks.

you can do it with the help of PreparedStatement.
Here the type of field(djwitem) and setmethod is should be match..i mean if the type of ur field is String then you need to use the setSting method.
you can do one thing specify one string variable.
String space=" ";
and now put this sapce variable at the second parameter of setString method.

How to retrieve a SQL query (in String format) from a PreparedStatement

Hello all,
I am in the process of unit testing an application accessing a Oracle 9i 9.2 RDBMS server with JDBC.
My query is:
As I have access to PreparedStatement and CallableStatement Java objets but not to the source queries which help create those objects?
Is thtere a simple way by using an API, to retrieve the SQL command (with possible ? as placeholders for parameters).
I have already looked at the API documentation for those two objets (and for the Statement and ResultSetmetaData objects too) but to no avail.
Thank you for any help on this issue,
Best regards,
Benoît

Sorry for having wasted your time... and for not understanding what you meant in your first reply.
But the codlet was only to show the main idea:
Here is the code which compiles OK for this approach to reach its intended goal:
main class (file TestSuiteClass.java):
import java.sql.*;
import static java.lang.Class.*;
* Created by IntelliJ IDEA.
* User: bgilon
* Date: 15/03/12
* Time: 10:05
* To change this template use File | Settings | File Templates.
public class TestSuiteClass {
public static void main(final String[] args) throws Exception {
// Class.forName("oracle.jdbc.OracleDriver");
final Connection mconn= new mConnection(
DriverManager.getConnection("jdbc:oracle:thin:scott/tiger@host:port:service"));
* final Statement lstmt= TestedClass.TestedMethod(mconn, ...);
* final String SqlSrc= mconn.getSqlSrc(lstmt).toUpperCase(), SqlTypedReq= mconn.getTypReq(lstmt);
* assertEquals("test 1", "UPDATE IZ_PD SET FIELD1= ? WHERE FIELDPK= ?", SqlSrc);
Proxy class (file mConnector.java):
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
* Created by IntelliJ IDEA.
* User: bgilon
* Date: 15/03/12
* Time: 10:05
* To change this template use File | Settings | File Templates.
* This file should be compiled with JDK 1.6, but can be used with previous JDK versions.
* See OKwith1pN booleans usage for not throwing Exceptions as Unknown methods by the conn object...
public final class mConnection implements Connection {
private final Connection conn;
private final List<Statement> Stmts= new ArrayList<Statement>();
private final List<String> SqlSrcs= new ArrayList<String>();
private final List<Integer> TypSrcs= new ArrayList<Integer>();
private final static String jvmv= System.getProperty("java.specification.version");
private static final boolean OKwith1p2;
private static final boolean OKwith1p4; /* OKwith1p5, */
private static final boolean OKwith1p6;
static {
/* jvmv= System.getProperty("java.version");
System.out.println("jvmv = " + jvmv);
jvmv= System.getProperty("java.vm.version");
System.out.println("jvmv = " + jvmv); */
System.out.println("jvmv = " + jvmv);
OKwith1p2= (jvmv.compareTo("1.2") >= 0);
OKwith1p4= (jvmv.compareTo("1.4") >= 0);
// OKwith1p5= (jvmv.compareTo("1.5") >= 0);
OKwith1p6= (jvmv.compareTo("1.6") >= 0);
public String getSqlSrc(final Statement pstmt) {
int ix= 0;
for(Statement stmt : this.Stmts) {
if(stmt == pstmt) return SqlSrcs.get(ix);
ix+= 1;
return null;
static private final String[] TypeNames= new String[] { "Statement", "PreparedStatement", "CallableStatement" };
public String getTypReq(final Statement pstmt) {
int ix= 0;
for(Statement stmt : this.Stmts) {
if(stmt == pstmt) return TypeNames[TypSrcs.get(ix)];
ix+= 1;
return null;
private void storedStatement(
final Statement stmt,
final String sqlSrc,
final Integer typReq
Stmts.add(stmt);
SqlSrcs.add(sqlSrc);
TypSrcs.add(typReq);
public Connection getDecoratedConn() {
return conn;
mConnection(final Connection pconn) {
this.conn= pconn;
public boolean isClosed() throws SQLException {
return conn.isClosed();
public void rollback(Savepoint savepoint) throws SQLException {
if(OKwith1p4) conn.rollback(savepoint);
public boolean isReadOnly() throws SQLException {
return conn.isReadOnly();
public int getTransactionIsolation() throws SQLException {
return conn.getTransactionIsolation();
public void setTransactionIsolation(int level)throws SQLException {
conn.setTransactionIsolation(level);
public Properties getClientInfo() throws SQLException {
return OKwith1p6 ? conn.getClientInfo() : null;
public <T> T unwrap(Class<T> iface)
throws SQLException {
return conn.unwrap(iface);
public void setAutoCommit(boolean auto) throws SQLException {
conn.setAutoCommit(auto);
public boolean getAutoCommit() throws SQLException {
return conn.getAutoCommit();
public Map<String,Class<?>> getTypeMap() throws SQLException {
if(!OKwith1p2) return null;
return conn.getTypeMap();
public void setTypeMap(Map<String,Class<?>> map) throws SQLException {
if(!OKwith1p2) return;
conn.setTypeMap(map);
public void setHoldability(final int holdability) throws SQLException {
if(OKwith1p4) conn.setHoldability(holdability);
public Struct createStruct(String typeName, Object[] attributes) throws SQLException {
return conn.createStruct(typeName, attributes);
public void commit() throws SQLException {
conn.commit();
public void rollback() throws SQLException {
conn.rollback();
public boolean isValid(int timeout) throws SQLException {
return OKwith1p6 && conn.isValid(timeout);
public void clearWarnings() throws SQLException {
conn.clearWarnings();
public int getHoldability() throws SQLException {
if(!OKwith1p4) return -1;
return conn.getHoldability();
public Statement createStatement() throws SQLException {
return conn.createStatement();
public PreparedStatement prepareStatement(final String SqlSrc) throws SQLException {
if(!OKwith1p2) return null;
final PreparedStatement lstmt= conn.prepareStatement(SqlSrc);
storedStatement(lstmt, SqlSrc, 1);
return lstmt;
public PreparedStatement prepareStatement(String sql, String[] columnNames) throws SQLException {
if(!OKwith1p4) return null;
final PreparedStatement lstmt= conn.prepareStatement(sql, columnNames);
storedStatement(lstmt, sql, 1);
return lstmt;
public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
final PreparedStatement lstmt= conn.prepareStatement(sql, resultSetType, resultSetConcurrency);
storedStatement(lstmt, sql, 1);
return lstmt;
public PreparedStatement prepareStatement(String sql, int[] columnIndexes) throws SQLException {
final PreparedStatement lstmt= conn.prepareStatement(sql, columnIndexes);
storedStatement(lstmt, sql, 1);
return lstmt;
public void setClientInfo(String name, String value) throws SQLClientInfoException {
if(OKwith1p6)
conn.setClientInfo(name, value);
public PreparedStatement prepareStatement(final String SqlSrc,
int resultType,
int resultSetCurrency,
int resultSetHoldability) throws SQLException {
final PreparedStatement lstmt= conn.prepareStatement(SqlSrc, resultType, resultSetCurrency);
storedStatement(lstmt, SqlSrc, 1);
return lstmt;
public PreparedStatement prepareStatement(final String SqlSrc,
int autogeneratedkeys) throws SQLException {
if(!OKwith1p4) return null;
final PreparedStatement lstmt= conn.prepareStatement(SqlSrc, autogeneratedkeys);
storedStatement(lstmt, SqlSrc, 1);
return lstmt;
public CallableStatement prepareCall(final String SqlSrc) throws SQLException {
final CallableStatement lstmt= conn.prepareCall(SqlSrc);
storedStatement(lstmt, SqlSrc, 2);
return lstmt;
public CallableStatement prepareCall(final String SqlSrc,
int resultType,
int resultSetCurrency,
int resultSetHoldability) throws SQLException {
if(!OKwith1p4) return null;
final CallableStatement lstmt= conn.prepareCall(SqlSrc, resultType, resultSetCurrency, resultSetHoldability);
storedStatement(lstmt, SqlSrc, 2);
return lstmt;
public Array createArrayOf(String typeName, Object[] elements) throws SQLException {
return OKwith1p6 ? conn.createArrayOf(typeName, elements) : null;
public CallableStatement prepareCall(final String SqlSrc,
int resultType,
int resultSetCurrency) throws SQLException {
if (!OKwith1p2) return null;
final CallableStatement lstmt= conn.prepareCall(SqlSrc, resultType, resultSetCurrency);
storedStatement(lstmt, SqlSrc, 2);
return lstmt;
public SQLXML createSQLXML() throws SQLException {
return OKwith1p6 ? conn.createSQLXML() : null;
public DatabaseMetaData getMetaData() throws SQLException {
return conn.getMetaData();
public String getCatalog() throws SQLException {
return conn.getCatalog();
public void setCatalog(final String str) throws SQLException {
conn.setCatalog(str);
public void setReadOnly(final boolean readonly) throws SQLException {
conn.setReadOnly(readonly);
public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
return conn.createStatement(resultSetType, resultSetConcurrency, resultSetHoldability);
public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
if(!OKwith1p2) return null;
return conn.createStatement(resultSetType, resultSetConcurrency);
public String nativeSQL(final String sql) throws SQLException {
return conn.nativeSQL(sql);
public void releaseSavepoint(Savepoint savepoint) throws SQLException {
if(OKwith1p4) conn.releaseSavepoint(savepoint);
public Savepoint setSavepoint() throws SQLException {
return OKwith1p4 ? conn.setSavepoint() : null;
public Savepoint setSavepoint(final String str) throws SQLException {
return OKwith1p4 ? conn.setSavepoint(str) : null;
public boolean isWrapperFor(Class iface) throws SQLException {
return conn.isWrapperFor(iface);
public String getClientInfo(final String str) throws SQLException {
return OKwith1p6 ? conn.getClientInfo(str) : null;
public void setClientInfo(final Properties pro) throws SQLClientInfoException {
if (OKwith1p6) conn.setClientInfo(pro);
public Blob createBlob() throws SQLException {
return OKwith1p6 ? conn.createBlob() : null;
public Clob createClob() throws SQLException {
return OKwith1p6 ? conn.createClob() : null;
public NClob createNClob() throws SQLException {
return OKwith1p6 ? conn.createNClob() : null;
public SQLWarning getWarnings() throws SQLException {
return conn.getWarnings();
public void close() throws SQLException {
conn.close();
Final word:
The final word about this is: there is currently three ways to obtain source SQL queries from compiled statement objects.
a) Use a proxy class the mConnector above;
b) Use a proxy JDBC driver as Log4JDBC;
c) Use the trace facility of the driver (however, post analyzing the logs would depend upon the driver selected).
Thank you for reading,
Benoît

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