Develop Reference

How to fix table already created and values not showing up in console with SQL in Java?

I'm in a Java class and the assignment is to create a table that will show the first ten values of pre-selected columns. However, when I run my code, with the sql running the way it is it says that my table is already created. I was wondering if there was a way for it to stop erroring out when that happens and to still show my code? Also when I set up a new table, the values that I need, (Income, ID, Pep) won't show up, just the headers I established before the syntax will. How would I make these fixes so it stops erroring out and I see my values in the console log?
This is running in eclipse, extended with prior project files from the class i'm taking. I've tried adding prepared statements, attempted to parse for strings to other variables and attempted syntax to achieve the values I need.
LoanProccessing.java file (Main file):
import java.sql.ResultSet;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
public class LoanProcessing extends BankRecords {
public static void main(String[] args) throws SQLException {
// TODO Auto-generated method stub
BankRecords br = new BankRecords();
br.readData();
Dao dao = new Dao();
dao.createTable();
dao.insertRecords(torbs); // perform inserts
ResultSet rs = dao.retrieveRecords();
System.out.println("ID\t\tINCOME\t\tPEP");
try {
while (rs.next()) {
String ID= rs.getString(2);
double income=rs.getDouble(3);
String pep=rs.getString(4);
System.out.println(ID + "\t" + income + "\t" + pep);
}
}
catch (SQLException e ) {
e.printStackTrace();
}
String s = "";
s=String.format("%10s\t %10s \t%10s \t%10s \t%10s \t%10s ", rs.getString(2), rs.getDouble(3), rs.getString(4));
System.out.println(s);
String timeStamp = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(Calendar.getInstance().getTime());
System.out.println("Cur dt=" + timeStamp);
Dao.java file:
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class Dao {
//Declare DB objects
DBConnect conn = null;
Statement stmt = null;
// constructor
public Dao() { //create db object instance
conn = new DBConnect();
}
public void createTable() {
try {
// Open a connection
System.out.println("Connecting to a selected database to create Table...");
System.out.println("Connected database successfully...");
// Execute create query
System.out.println("Creating table in given database...");
stmt = conn.connect().createStatement();
String sql = "CREATE TABLE A_BILL__tab " + "(pid INTEGER not NULL AUTO_INCREMENT, " + " id VARCHAR(10), " + " income numeric(8,2), " + " pep VARCHAR(4), " + " PRIMARY KEY ( pid ))";
stmt.executeUpdate(sql);
System.out.println("Created table in given database...");
conn.connect().close(); //close db connection
} catch (SQLException se) {
// Handle errors for JDBC
se.printStackTrace();
}
}
public void insertRecords(BankRecords[] torbs) {
try {
// Execute a query
System.out.println("Inserting records into the table...");
stmt = conn.connect().createStatement();
String sql = null;
// Include all object data to the database table
for (int i = 0; i < torbs.length; ++i) {
// finish string assignment to insert all object data
// (id, income, pep) into your database table
String ID = torbs[i].getID();
double income=torbs[i].getIncome();
String pep=torbs[i].getPep();
sql = "INSERT INTO A_BILL__tab(ID,INCOME, PEP) " + "VALUES (' "+ID+" ', ' "+income+" ', ' "+pep+" ' )";
stmt.executeUpdate(sql);
}
conn.connect().close();
} catch (SQLException se) { se.printStackTrace(); }
}
public ResultSet retrieveRecords() {
ResultSet rs = null;
try {
stmt = conn.connect().createStatement();
System.out.println("Retrieving records from table...");
String sql = "SELECT ID,income,pep from A_BILL__tab order by pep desc";
rs = stmt.executeQuery(sql);
conn.connect().close();
} catch (SQLException se) { se.printStackTrace();
}
return rs;
}
}
Expected results would be printlns for the table functions (inserting records and so on), the headings, the data values for the first 10 files, and the date and time of when the program was run. Actual results were some of the table functions, headings and then the time when the program ran not including when it errors me out with table already created. I'm not exactly sure where or how to fix these issues.

you're getting this exception because every time you run your code, your main method calls dao.createTable();, and if the table is already created, it will throw an exception. So for this part, use a verification to check if the table is already created.
I'm not really sure where you created the variable torbs, but also make sure its properties are not null before inserting them to the database.

Unexpected Token: AS (Using UCanAcces.jar)

I can't find the mistake, I get this error:
Error: net.ucanaccess.jdbc.UcanaccessSQLException: unexpected token: = required: AS
This is my code. Can you help me find it? Thanks in advance.
package database;
// Imports
import java.sql.*;
public class DBConnect {
// Path to Database
final static String DB = "jdbc:ucanaccess://src/database/DB.accdb";
// Declareren
public static String strAntwoord1;
public void Connect(){
// Initialiseren
Connection con;
Statement s;
ResultSet rs = null;
// Try Database Path/Connection to get Variables
try {
con = DriverManager.getConnection(DB);
s = con.createStatement();
rs = s.executeQuery("SELECT * FROM tblAntwoorden WITH ID=1");
if (rs != null) while ( rs.next() ) {
strAntwoord1 = rs.getString("Antwoord");
if (strAntwoord1 == "Indonesië"){
System.out.println("Antwoord found.");
}
}
s.close();
con.close();
} catch (SQLException e) {
System.out.println("Error: " + e);
}
}
}
It's a task for school and I've got to solve this before midnight. So I've got 1 hour left. Thanks in advance for the people who are willing to help me.

Benji, your SQL has to be perfectioned. Not WITH but WHERE:
SELECT * FROM tblAntwoorden WHERE ID=1
The message says "an alias declaration is expected", e.g.,
SELECT * FROM tblAntwoorden AS a WHERE a.ID=1
yet I hope this suggestion from a different timezone helps you to do the next homework.

Looking up data in database from user

I am trying to let a user lookup a football result, and the database displays that result from the database, but i keep getting this error:
Exception in thread "main" java.sql.SQLException: [Microsoft][ODBC Microsoft Access Driver] Too few parameters. Expected 1.
This is my "useFootballBean.java" bean:
package results;
import results.*;
import java.util.*;
import java.sql.*;
public class UseFootballBean
{
public static void main(String[] args)
throws SQLException, ClassNotFoundException
{
Scanner keyboard = new Scanner(System.in);
String home;
ResultsBean resultsBean = new ResultsBean();
System.out.print("\nEnter Team: ");
home = keyboard.next();
home = resultsBean.getHome(home);
if (home.equals(null))
System.out.println(
"\n*** No such Team ***");
else
System.out.println("\nTeam " + home);
}
}
This is my "resultsBean.java" bean
package results;
import java.sql.*;
public class ResultsBean
{
private Connection connection;
private Statement statement;
private ResultSet results;
public String getHome(String enter)
throws SQLException, ClassNotFoundException
{
String query;
String team = null;
connectAndCreateStatement();
query = "SELECT * FROM Results WHERE homeTeam = "
+ enter;
results = statement.executeQuery(query);
if (results.next())
team = results.getString("homeTeam");
connection.close();
return team;
}
private void connectAndCreateStatement()
throws SQLException, ClassNotFoundException
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
connection = DriverManager.getConnection(
"jdbc:odbc:FootballData","","");
statement = connection.createStatement();
}
}

I think you are missing the single quotes required in where clause of query while comparing against a string value. Here you go:
where keyword_name='"+keyword_name+"'"
query = "SELECT * FROM Results WHERE homeTeam = " + '"+ enter + "'";

Since your query parameter is a string, you need to enclose it in quotes:
"SELECT * FROM Results WHERE homeTeam = '" + enter + "'";
However, this is still a bad approach, because it leaves you vulnerable to SQL injection (Remember Bobby Tables?), and will break if the user enters a team name containing quote characters (like England's Greatest Team). Therefore, you should use a PreparedStatement (see Java tutorial).

You are missing single quotation in your Sql Query
query = "SELECT * FROM Results WHERE homeTeam = '"
+ enter+"'";
OR with PreparedStatement to accept quotation
PreparedStatement stmt = null;
String sql;
ResultSet rows=null
try {
sql = "select * from Results where homeTeam=?"
stmt = theConn.prepareStatement(sql);
stmt.setString(1, "Team with ' are permitted!");
rows = stmt.executeQuery();
stmt.close();
}
catch (Exception e){
e.printStackTrace();
}
finally { if (stmt != null) {
stmt.close();
}
Thanks

Java mysql, Simple update with PreparedStatement has syntax error

This code has some sort of simple syntax error. I've fought it for hours now and I give up. Can you spot it? I bet it's easy. Thanks!
When I update just the firstname John, no problem.
When I try to update the commented out line for the lastname too, syntax error.
import java.sql.*;
public class UpdateTester {
public static void main(String[] args) {
try {
Connect connect = new Connect();
Connection connection = connect.getConnection();
try {
String sql = "UPDATE student SET firstName = ? "
+ " WHERE studentID = 456987";
//String sql = "UPDATE student SET firstName = ? "
// + " Set lastName = ?, "
// + " WHERE studentID = 456987";
PreparedStatement pst = connection.prepareStatement(sql);
pst.setString(1, "John");
//pst.setString(2, "Johnson");
pst.executeUpdate();
System.out.println("Updated Successfully!");
connection.close();
} catch (SQLException e) {
System.out.println("Exception 1!");
e.printStackTrace();
}
} catch (Exception e) {
System.out.println("Exception 2!");
e.printStackTrace();
}
}
}
Column names are correct.
Updating just the lastname on it's own works correctly too.
Update fails with syntax error when trying to do both, as in the commented out lines.

3 issues:
The SET keyword can only appear once in an UPDATE statement:
Comma before second parameter missing
Unnecessary comma before where clause
The corrected syntax:
String sql = "UPDATE student SET firstName = ?, "
+ " lastName = ? "
+ " WHERE studentID = 456987";
SQL Reference

Why ‘No database selected’ SQLException? [duplicate]

This question already has answers here:
java.sql.SQLException: No database selected - why?
(4 answers)
Closed 3 years ago.
why this program is not executing when it goes in to the do while loop second time and why it is giving the exception "Exception java.sql.SQLException: [MySQL][ODBC 5.1 Driver][mysqld-5.0.51a-community-nt]No database selected"
//import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
import java.util.Vector;
public class DataBase {
public void LoadDriver() {
// Load the JDBC-ODBC bridge driver
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
} catch (ClassNotFoundException ee) {
ee.printStackTrace();
}
}
// 2.open a data source name by means of the jdbcodbcdriver.
static void connect() throws SQLException {
// Connect to the database
Connection con = DriverManager.getConnection("jdbc:odbc:MySQL", "root", "admin");
Statement stmt = con.createStatement();
// Shut off autocommit
con.setAutoCommit(false);
System.out.println("1.Insert 2.Delete 3.Update 4.Select");
Scanner s = new Scanner(System.in);
int x;
x = s.nextInt();
String query; // SQL select string
ResultSet rs; // SQL query results
boolean more; // "more rows found" switch
String v1, v2; // Temporary storage results
Vector<Object> results = new Vector<Object>(10);
if (x == 1) {
try {
stmt.executeUpdate("INSERT INTO employee( emp_id,emp_name ) VALUES ( '122','shiva' ) ");
} catch(Exception e){System.out.println("Exception " +e);e.printStackTrace();}
}
if (x == 2) {
try {
stmt.executeUpdate("DELETE from employee where emp_id='102' ");
}catch(Exception e){System.out.println("Exception "+e);e.printStackTrace();}
}
if (x == 3) {
try {
stmt
.executeUpdate("UPDATE employee SET emp_name = 'madavan' where emp_id='20'; ");
} catch(Exception e){System.out.println("Exception "+e);e.printStackTrace();}
}
query = "SELECT * FROM employee ";
try {
rs = stmt.executeQuery(query);
// Check to see if any rows were read
more = rs.next();
if (!more) {
System.out.println("No rows found.");
return;
}
// Loop through the rows retrieved from the query
while (more) {
v1 = "ID: " + rs.getInt("emp_id");
v2 = "Name: " + rs.getString("emp_name");
System.out.println(v1);
System.out.println(v2);
System.out.println("");
results.addElement(v1 + "\n" + v2 + "\n");
more = rs.next();
}
rs.close();
} catch (SQLException e) {
System.out.println("" + results.size() + "results where found.");
}
finally{stmt.close();}
}
public static void main(String[] args) throws SQLException {
String str = "y";
do {
DataBase s = new DataBase();
s.LoadDriver();
DataBase.connect();
Scanner sc = new Scanner(System.in);
System.out.println("DO u Want to PROCEED TO QUERY : ");
str = sc.next();
} while (str !="n");
}
}

Unless you have to use the jdbc/odbc driver I would use the straight mysql jdbc driver. You can download it free from mysql.
then
public void LoadDriver() {
// Load the JDBC-ODBC bridge driver
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException ee) {
ee.printStackTrace();
}
}
static void connect() throws SQLException {
// Connect to the database
Connection con = DriverManager.getConnection("jdbc:mysql:host/databasename", "root", "admin");
Statement stmt = con.createStatement();
...

Just from looking at the exception.. I would guess that you are not specifying the database.
How can you do a select on a table without telling it which schema to select from ?
This is typically set in the connection string..

Is the ODBC source actually set up to select a database? eg. can you access the database through another ODBC client tool?
If you need to select a database explicitly in the JDBC string you can do that using the ‘database’ parameter.
But having the database chosen in the ODBC setup would be more usual. And indeed, as Clint mentioned, using the normal MySQL JDBC driver instead of ODBC would be more usual still.
while (str !="n")
That's not how you compare strings in Java.

Found a bug listing at MySQL that gives this error but with different technologies. However, in the description it indicates that it is related to reauthorization not sending the database information, so perhaps that is what you are encountering here as well.
Some things that stick out as odd to me (although no clue if they will have any impact on your error)
You only need to load the Driver Manager once
You aren't closing your connection, so either close it or refactor to use the same one.
Perhaps move these two lines to just before the do loop
DataBase s = new DataBase();
s.LoadDriver();