Unable to query mysql database using jdbc preparedstatement

Question

I am trying to run the below jdbc code to get the object key:

String sqlSelectObjKey = "select OBJ_KEY from obj where OBJ_NM=? and OBJ_TYP_CD='CONN';";


    PreparedStatement statement = null;
    ResultSet rs = null;
    try {           
        statement = connection.prepareStatement(stmtSelectObjKey);
        statement.setString(1, "Postal Connector");

        rs = statement.executeQuery(stmtSelectObjKey);
        while(rs.next()) {
            this.executionLog.setObjKey(rs.getInt("OBJ_KEY"));
        }

    } catch (SQLException e1) {
        e1.printStackTrace();

    } finally {
        if (rs != null) try { rs.close(); } catch (SQLException ignore) {}
        if (statement != null) try { statement.close(); } catch (SQLException ignore) {}
    }

But every time it results in below exception:

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '? and OBJ_TYP_CD='CONN'' at line 1
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
    at com.mysql.jdbc.Util.getInstance(Util.java:360)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:978)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3887)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3823)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2435)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2582)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2526)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2484)
    at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1446)
    at appMetadata.ConnectorMetadataLoad.insertExecutionLog(ConnectorMetadataLoad.java:67)
    at appCore.PostalCodeInterface.getPostalData(PostalCodeInterface.java:37)
    at appMain.PostalDataConnector.getPostalData(PostalDataConnector.java:19)
    at PostalDemo.main(PostalDemo.java:14)

Removing the place holder and setting the value directly works fine.

I am not sure where the syntax is wrong, I will appreciate if anyone can point out the error.

Answer 1

I got Your error, why you are assigning the query again to the preparedstatment.

Your Code:

statement = connection.prepareStatement(stmtSelectObjKey);
statement.setString(1, "Postal Connector");
rs = statement.executeQuery(stmtSelectObjKey);

Code Should be:

statement = connection.prepareStatement(stmtSelectObjKey);
statement.setString(1, "Postal Connector");
rs = statement.executeQuery();

Thats why you are getting syntax error for the ?. Hope this helps you

Answer 2

remove the ; in your sql string and try it again.

the ; is used in the most db-tools to seperate sql-strings but it is no standard sql.

Answer 3

instead of

statement.executeQuery(stmtSelectObjKey);

use

statement.executeQuery();

it will work !!

Answer 4

As you using prepareStatement the execute syntax is like below prepareStatement.executeQuery() So change your code like below

String sqlSelectObjKey = "select OBJ_KEY from obj where OBJ_NM=? and OBJ_TYP_CD='CONN';";


    PreparedStatement statement = null;
    ResultSet rs = null;
    try {           
        statement = connection.prepareStatement(stmtSelectObjKey);
        statement.setString(1, "Postal Connector");

        rs = statement.executeQuery();//Change is here
        while(rs.next()) {
            this.executionLog.setObjKey(rs.getInt("OBJ_KEY"));
        }

    } catch (SQLException e1) {
        e1.printStackTrace();

    } finally {
        if (rs != null) try { rs.close(); } catch (SQLException ignore) {}
        if (statement != null) try { statement.close(); } catch (SQLException ignore) {}
    }

For more information click here

Answer 5

Replace below query

String sqlSelectObjKey = "select OBJ_KEY from obj where OBJ_NM=? and OBJ_TYP_CD='CONN';";

with

String sqlSelectObjKey = "select OBJ_KEY from obj where OBJ_NM=? and OBJ_TYP_CD='CONN'";