Good morning developers (Its morning in Kenya). I have been working with Java and MySql databases. my newest client want me to create a solution based on his current installed database, running Microsoft Sql Server 2014 Enterprise Edition.
The code below connects to the SQL Server instance but cannot transact any SQL Statements. i get the SQL Exception "Invalid Object Name". Please troubleshoot the code for me. thank you.
private java.sql.`enter code here`Connection con = null;
private final String url = "jdbc:sqlserver://";
private final String serverName = "localhost\\PHILIP";
private final String portNumber = "1433";
private final String databaseName = "Payrol";
private final String userName = "sa";
private final String password = "kukaphilip";
public Main() {
System.setProperty("java.net.preferIPv6Addresses", "true");
getConnection();
}
private String getConnectionUrl() {
//System.out.println(java.lang.System.getProperty("java.library.path"));
return "jdbc:jtds:sqlserver://localhost;Database=Payrol;integratedSecurity=true";
}
private java.sql.Connection getConnection() {
try {
/*Class.forName("net.sourceforge.jtds.jdbc.Driver");*/
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
con = DriverManager.getConnection(getConnectionUrl());
if (con != null) {
System.out.println("Connection Successful!");
String sql = "INSERT INTO payrol.dbo.test values('1','Philip')";
Statement st = con.createStatement();
st.executeUpdate(sql);
/*st.setInt(1, 1);
st.setString(2, "Philip");
st.execute();*/
}else{
System.out.println("Connection failed");
}
} catch (SQLException e) {
System.out.println(e.getMessage());
} catch (ClassNotFoundException ex) {
Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
}
return con;
}
Check These
1)Try executing same query in SSMS to see if you get any error.
2)Put payrol.dbo.test into square brackets like [payrol].[dbo].[test]
3) If collation is case sensitive the cases of 'test' must be identical in database and in your query.
Related
I'm sorry for my question but can't solve this problems myself. Read different topics here and tried to read tutuorials...
I have MySQL server v8, and trying to start simple example in java to get data from server.
I set up classpat as system variable, put here mysql-connector-java-8.0.13.jar. Comman echo %CLASSPATH% shows it properly. Also i put connector in all project folders xD (didn't help either).
import java.sql.*;
public class file_test {
// JDBC URL, username and password of MySQL server
private static final String url = "jdbc:mysql://localhost:3306/MySQL80";
private static final String user = "root";
private static final String password = "123";
// JDBC variables for opening and managing connection
private static Connection con;
private static Statement stmt;
private static ResultSet rs;
public static void main(String args[]) {
String query = "select count(*) from actor";
try {
// opening database connection to MySQL server
con = DriverManager.getConnection(url, user, password);
// getting Statement object to execute query
stmt = con.createStatement();
// executing SELECT query
rs = stmt.executeQuery(query);
while (rs.next()) {
int count = rs.getInt(1);
System.out.println("Total number of actors in the table : " + count);
}
} catch (SQLException sqlEx) {
sqlEx.printStackTrace();
} finally {
//close connection ,stmt and resultset here
try {
con.close();
} catch (SQLException se) { /*can't do anything */ }
try {
stmt.close();
} catch (SQLException se) { /*can't do anything */ }
try {
rs.close();
} catch (SQLException se) { /*can't do anything */ }
}
}
}
Problem is when i try to start projest, IJ says:
"C:\Program Files\Java\jdk-11.0.2\bin\java.exe" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA\lib\idea_rt.jar=63236:C:\Program Files\JetBrains\IntelliJ IDEA\bin" -Dfile.encoding=UTF-8 -classpath F:\work\program\file_test\out\production\file_test file_test
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/MySQL80
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:702)
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:228)
at file_test.main(file_test.java:21)
Exception in thread "main" java.lang.NullPointerException
at file_test.main(file_test.java:38)
Process finished with exit code 1
I want to run this code from IJ and get data from DB as a result.
I am using android studio to develop an application and using Azure Sql Server to host my database. The problem is I was able to connect to my database on SQL server but it has an error of Object not found in my database.
I found out that it might be connecting to my master database instead of the database I want it to connect to. Is there any solution to solve the problem?
package com.example.lenovo.testing1;
import android.annotation.SuppressLint;
import android.os.StrictMode;
import android.util.Log;
import java.sql.*;
public class ConnectionClass {
String hostName = "haozailai.database.windows.net";
String dbName = "haozailai";
String user = "username";
String password = "password";
#SuppressLint("NewApi")
public Connection CONN() {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
String ConnURL;
Connection conn = null;
try {
Class.forName("net.sourceforge.jtds.jdbc.Driver");
String url = String.format("jdbc:jtds:sqlserver://haozailai.database.windows.net:1433;database=haozailai;user=username;password=password;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;");
conn = DriverManager.getConnection(url);
}catch (SQLException se)
{
Log.e("error here 1 : ", se.getMessage());
}
catch (ClassNotFoundException e)
{
Log.e("error here 2 : ", e.getMessage());
}
catch (Exception e)
{
Log.e("error here 3 : ", e.getMessage());
}
return conn;
}
}
Picture of my database structure
I tried to connect my sqlserver via java jdbc and did not reproduce your issue.
I can connect to my application db successfully.
My test code:
import java.sql.*;
public class Test {
public static final String url = "jdbc:sqlserver://***.database.windows.net:1433;database=***;user=***password=***;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;";
public static final String name = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
public static Connection conn = null;
public static PreparedStatement pst = null;
public static Statement stmt = null;
public static ResultSet rs = null;
public static void main(String[] args) {
try {
String SQL = "select * from dbo.Student";
Class.forName(name);
conn = DriverManager.getConnection(url);
stmt = conn.createStatement();
rs = stmt.executeQuery(SQL);
while (rs.next()) {
System.out.println(rs.getString("name"));
}
close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void close() {
try {
conn.close();
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
After some research, I found out it is because of your connect url.
You need to modify your connect url ：
jdbc:jtds:sqlserver://haozailai.database.windows.net:1433/<your application db name> ...
You could refer to the pages below for more details.
https://sourceforge.net/p/jtds/discussion/104389/thread/a672d758/
how to connect sql server using JTDS driver in Android
Update answer:
I have made a slight adjustment to your connect URL and can connect to my application database normally.
try {
String SQL = "select * from dbo.Student";
Class.forName("net.sourceforge.jtds.jdbc.Driver");
String url = String.format("jdbc:jtds:sqlserver://***.database.windows.net:1433/<your database name>;user=***;password=***;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;");
conn = DriverManager.getConnection(url);
stmt = conn.createStatement();
rs = stmt.executeQuery(SQL);
while (rs.next()) {
System.out.println(rs.getString("name"));
}
close();
} catch (Exception e) {
e.printStackTrace();
}
Notice that remove the database=*** and add "/<your database name>" after your host string.
Please refer to the above code and try again.Any concern, please let me know.
Hope it helps you.
I know this answer is waay too late, but I found this video that totally works: https://www.youtube.com/watch?v=WJBs0zKGqH0
The thing is, you have to download a jtds jar, the guy in the video says where you can get it from and also, you need to add "jtds" before "sqlserver" in connection url and edit the way the 'databe' is written in the connection url, like this:
jdbc:jtds:sqlserver://serverName.database.windows.net:portNr:DatabaseName=dbName;user=....
I wrote a java program which retrieve data from a PG gb, process them, and write them in an Oracle DB.
While the PG part is fully working, the Oracle one has issues.
I can connect to the DB, but every query ends with a rollback (ResultSet with Oracle is always null)
Of course i have both PG and Oracle JDBC driver.
Here are my DBs object and testing queries
private final static PostgresDB postgres = new PostgresDB("jdbc:postgresql://192.168.2.23:5432/T18CLEAN", "myPGUser", "myPGPasswd", true);
private final static OracleDB oracle = new OracleDB("jdbc:oracle:thin:#192.168.2.20:1521/EFFEVI.T18FV.IT", "myOracleUser", "myOraclePasswd");
private final static String testPostgres = "SELECT product_pricelist_item.x_product_name FROM public.product_pricelist_item;";
private final static String testOracle = "SELECT EFFEVI.PRESA_ORDINI.PO_CLIENTE FROM EFFEVI.PRESA_ORDINI;";
Then I setup the 2 connections:
PG:
public Connection getConnect() throws ClassNotFoundException {
System.out.println("-------- Posgres JDBC Connection Testing ------");
String url = c_url;
Connection conn = null;
Properties props = new Properties();
props.setProperty("user", user);
props.setProperty("password", passwd);
props.setProperty("ssl", boolToString(sslEnabled));
try{
Class.forName("org.postgresql.Driver");
System.out.println("Postgres JDBC Driver Registered!");
} catch(ClassNotFoundException e) {
System.out.println("Where is your Oracle JDBC Driver?");
e.printStackTrace();
return null;
}
try {
conn = DriverManager.getConnection(url, props);
System.out.println("You made it, take control your Postgres database now!");
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("Failed to make connection to Postgres DB!");
}
return conn;
}
Oracle:
public Connection getConnect(){
Connection connection = null;
System.out.println("-------- Oracle JDBC Connection Testing ------");
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your Oracle JDBC Driver?");
e.printStackTrace();
return connection;
}
System.out.println("Oracle JDBC Driver Registered!");
try {
connection = DriverManager.getConnection(c_url, user, passwd);
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
e.printStackTrace();
return connection;
}
if (connection != null) {
System.out.println("You made it, take control your Oracle database now!");
return connection;
} else {
System.out.println("Failed to make connection to Oracle DB!");
}
return connection;
}
After all these pass i perform queries
public ResultSet executeCommand(Connection c, String command) {
Statement st = null;
ResultSet rs = null;
try {
st = c.createStatement();
rs = st.executeQuery(command);
} catch (SQLException e) {
}
if(rs==null){
System.out.println("Failed to Execute command " + command);
} else {
System.out.println("Command Executed: " + command);
}
return rs;
}
Assuming that there are no parameters error... What could it be? Any help?
Thank you very much
Remove a semicolon at the end of the query.
Use this:
private final static String testOracle =
"SELECT EFFEVI.PRESA_ORDINI.PO_CLIENTE FROM EFFEVI.PRESA_ORDINI";
instead of this one:
private final static String testOracle =
"SELECT EFFEVI.PRESA_ORDINI.PO_CLIENTE FROM EFFEVI.PRESA_ORDINI;";
Also don't silently "swallow" an exception in your code:
} catch (SQLException e) {
}
Rethrow the exception, or at least print the error to the log:
} catch (SQLException e) {
log.error("Error while executing query " + command, e);
throw new RuntimeException("Error while executing query " + command, e);
}
I am pretty new to Java so I'm working on a project to develop my knowledge with databases and Java.
I have figured out how to add queries into the database but now I'm getting errors when trying to print them out.
Assume I already have everything that's necessary imported in such as the scanner and sql statements
Here is my connection class which is named MainClass:
public static Connection getConnection() throws Exception {
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/testTable";
String username = "placeholder";
String password = "placeholder";
Class.forName(driver);
Connection conn = Driver Manager.getConnection(url, username, password);
return conn;
}
Now in a different class if the user types !lookup and a word I want the definition of that word to be retrieved from the table whose name is dictionary and columns are word, definition:
String userSearch = user_input.next();
String[] userSearchSplit = userSearch.split(" ", 3);
if (userSearchSplit[0].equals("!lookup")) {
try {
conn = MainClass.getConnection();
String query = "select definition from dictionary where word=" + userSearchSplit[1];
ResultSet result = pstmt.executeQuery(query);
while (result.next()) {
String definition = result.getString("definition");
System.out.println(definition);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
At the end of all this when I try to look up a word I put in the table before running I get:
java.lang.NullPointerException
Check if your user_input is null?
I am assuming your code:
ResultSet result = pstmt.executeQuery(query);
as
Statement pstmt = conn.createStatement();
ResultSet result = pstmt.executeQuery(query);
Or it could be that you have not initialized the pstmt properly
I'm working on a web project and I recently installed postgres 9.1.1
The postgresql server is up and running. I can connect via psql as usual and everything is loaded and properly saved from a dump of the db I made from 8.5.
So I also downloaded the JDBC4 driver for 9.1 postgres version here:
http://jdbc.postgresql.org/download/postgresql-jdbc-9.1-901.src.tar.gz
I added it to the java build path using the project properties via eclipse.
This is the code I use to provide db connection to other classes (i.e. it's a singleton, I get a new connection only if the existing is either closed or null, from one object at a time only)
public abstract class DBConnection {
private static Connection connection = null;
public static void connect() {
try {
if (connection == null) {
String host = "127.0.0.1";
String database = "xxxxx";
String username = "xxxxx";
String password = "xxxxx";
String url = "jdbc:postgresql://" + host + "/" + database;
String driverJDBC = "org.postgresql.Driver";
Class.forName(driverJDBC);
connection = DriverManager.getConnection(url, username,
password); //line firing the class not found exception
} else if (connection.isClosed()) {
connection = null;
connect();
}
} catch (SQLException e) {
e.printStackTrace(System.err);
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
public static void disconnect() {
if (connection != null) {
try {
connection.close();
} catch (SQLException e) {
Logger.getLogger(DBConnection.class.getName()).log(
Level.SEVERE, null, e);
}
}
}
public static Connection getConnection() {
try {
if (connection != null && !connection.isClosed()) {
return connection;
} else {
connect();
return connection;
}
} catch (SQLException e) {
Logger.getLogger(DBConnection.class.getName()).log(Level.SEVERE,
null, e);
return null;
}
}
#Override
public void finalize() {
if (connection != null) {
try {
connection.close();
} catch (SQLException e) {
Logger.getLogger(DBConnection.class.getName()).log(
Level.SEVERE, null, e);
}
}
}
}
As I wrote in the title when I run the project and a class asks for a connection to this class I always get a Class Not Found Exception, Since it apparently can't load the org.postgresql.Driver.class The driver is located in a subfolder of the project ~/lib/org.postgresql-9.1-901.jdbc4.jar and as I said added to the build path via eclipse project properties.
I'm also providing a sample query to let see the usual behavior of my classes to access the DBConnection:
public static final User validateUserCredentials(String id, String pswd) {
Connection connection = DBConnection.getConnection();
Logger.getLogger(Credentials.class.getName()).log(Level.SEVERE, (connection!=null)?"connection not null":"connection null");
Statement stmt = null;
Logger.getLogger(Home.class.getName()).log(Level.SEVERE, "validating credentials for user: username : " + id + " password : " + pswd);
String sql = "Select * from fuser where id = '" + id + "'";
ResultSet resultset = null;
try {
stmt = connection.createStatement();
resultset = stmt.executeQuery(sql);
Logger.getLogger(Credentials.class.getName())
.log(Level.SEVERE, sql);
resultset.next();
String password = resultset.getString("pswd");
if (pswd.equals(password))
return new User(id, pswd);
} catch (SQLException ex) {
Logger.getLogger(Credentials.class.getName()).log(Level.SEVERE,
null, ex);
} finally {
if (stmt != null)
stmt = null;
if (resultset != null)
resultset = null;
if (connection != null) {
try {
connection.close();
} catch (SQLException e) {
}
connection = null;
}
}
return null;
}
I'm working on a web project and I recently installed postgres 9.1.1
...
I added it to the java build path using the project properties via eclipse.
That's the wrong way. That JAR has to be dropped straight in /WEB-INF/lib folder of the web project without fiddling with the Build Path in the project's properties. That folder is standard part of webapp's runtime classpath.
Unrelated to the concrete problem: you've a major design flaw in your DBConnection class. You've declared Connection as static which essentially makes your connection not threadsafe. Use a connection pool and never assign the Connection (nor Statement nor ResultSet) as a class/instance variable. They should be created and closed in the very same try-finally block as where you're executing the query. Further you've there also a SQL injection hole. Use PreparedStatement instead of concatenating user-controlled variables in the SQL string.
See also:
JDBC MySql connection pooling practices to avoid exhausted connection pool
Get database connection from a connection pool
Am I Using JDBC Connection Pooling?
Add this dependency in your pom:
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.4-1203-jdbc4</version>
</dependency>
The first thing I'd do is unpack the jar and confirm that the driver is really in there as org.postgresql.Driver. I notice when looking at jarfinder and related sites that there isn't a Postgres 9.x jar containing org.postgresql.Driver.