Thread: JDBC, PrepareStatement and TimeStamp problem

JDBC, PrepareStatement and TimeStamp problem

From

Jeffrey Leegon

Date:

10 January 2006, 20:09:10

I get an error with the timestamps when running the following code:
(Varibbles currentTrainStart and stop are GregorianCalendars)
String tableName = "\"AdultData\"";


  String tempSql = "SELECT

\"Age\",\"Gender\",\"PrimaryLanguage\",\"TimeOfDay\",\"DayOfWeek\",\"ChiefComplaint\",\"BodyFluidIso\",\"RespIso\",\"Acuity\",\"Consult\",\"Labs\",\"Radiology\",";
             tempSql+= "\"EKG\",\"MOA\",\"Admitted\" FROM ? ";
             tempSql +="WHERE \"DATE_ADMITTED\">= ? AND
\"DATE_ADMITTED\"< ? ;";
             query = conn.prepareStatement(tempSql);


        query.setString(1, tableName);
        Timestamp startTrain = new
Timestamp(currentTrainStart.getTimeInMillis());
        query.setTimestamp(2,startTrain);
        Timestamp stopTrain = new Timestamp(stop.getTimeInMillis());
        query.setTimestamp(3, stopTrain);

        System.out.println(query.toString());


        query.executeQuery();
        // query.clearParameters();

When I execute the following code I get the error:

java.sql.SQLException: ERROR: syntax error at or near "$1"
    at
org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:1482)
    at
org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1267)
    at
org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:186)
    at
org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:392)
    at
org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:330)
    at
org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:240)
    at TemporalDataSetCreator.getNextDataSet(TemporalDataSetCreator.java:180)
    at SequentialBNTest.main(SequentialBNTest.java:31)

After initiating the places holders in the prepared statement and call
toString() I get the following line going to the DB:

SELECT

"Age","Gender","PrimaryLanguage","TimeOfDay","DayOfWeek","ChiefComplaint","BodyFluidIso","RespIso","Acuity","Consult","Labs","Radiology","EKG","MOA","Admitted"

FROM "AdultData" WHERE "DATE_ADMITTED">= 2004-05-10 00:00:00.000000+0100
AND "DATE_ADMITTED"< 2004-05-31 00:00:00.000000+0100

Which if I put in pgAdmin III and add single quotes around the
Timestamps if runs fine. If I add \' around the ? in the prepared
statement it gives the ? to the DB and throws and error. What am I doing
wrong?

Thanks,
Jeff

Re: JDBC, PrepareStatement and TimeStamp problem

From

Kris Jurka

Date:

10 January 2006, 20:12:03

On Tue, 10 Jan 2006, Jeffrey Leegon wrote:

> String tableName = "\"AdultData\"";
> String tempSql = "SELECT [some stuff] FROM ? WHERE [some conditions]";
> query = conn.prepareStatement(tempSql);
> query.setString(1, tableName);
>
> java.sql.SQLException: ERROR: syntax error at or near "$1"
>     at

You cannot use placeholders for stuctural parts of your query, only
parameters.  The server cannot create a prepared plan if it doesn't even
know what table you are operating on.

Kris Jurka