Oracle invalid identifier doesnt understand string

问题

I'm having an issue with my query not working. This is the command variable.

When it executes it should be retrieving the tuples that have BSc as their degree. I have tested this in oracle directly and the query returns these. It is identical to the command statement.

When I print out command, the line looks exactly the same as my command that worked in oracle.

SELECT distinct fname, lname, student_id FROM student where degree='BA';

Yet, it should be printing out to the screen. The tables are loaded into oracle already.

I've been racking my brain with this issue but can't seem to find a fix!

The error I keep getting is: ORA-00911: invalid character

What I do is I store in degree the result from scanner which is a string. So concatenating it in the command variable shouldn't make an issue -- the query looks identical to what works in oracle.

Could it be because it wants a char instead of a string? If it does, then how would I get it to make "BSc" as a char? Concatenating chars sounds dumb.

Relevant code below:

 private String getDegree() {
  Scanner scan = new Scanner(System.in);
  System.out.println("Please enter degree code (either BA or BSc)");
  return scan.next();

}

//get the degree name
        String degree = getDegree();


        //get statement and execute appropriate select
        Statement stmt = con.createStatement();
        String command = "SELECT distinct fname, lname, student_id FROM student"+
           " where degree='"+ degree + "';";
        System.out.println(command);
        ResultSet result = stmt.executeQuery(command);

        //determine number of columns
        ResultSetMetaData metadata = result.getMetaData();
        int columns = metadata.getColumnCount();

        //print heading
        System.out.println("\nFNAME        LNAME         STUD_ID");
        System.out.println("====================================");

        //loop through result and print columns

        while (result.next()){
           for (int i=1; i <=columns; i++){
              System.out.print(result.getString(i)+spaces(15-result.getString(i).length()));
           }
           System.out.println();
        }

回答1:

In JDBC your SQL statement should not be terminated by semicolon.

Change

String command = "SELECT distinct fname, lname, student_id FROM student"+
       " where degree='"+ degree + "';";

String command = "SELECT distinct fname, lname, student_id FROM student"+
       " where degree='"+ degree + "'";

来源：https://stackoverflow.com/questions/25958116/oracle-invalid-identifier-doesnt-understand-string

标签

java

sql

database

Oracle

tuples