Fill textboxes with null values - java

I'm writing a Webapp where there is data that has to be pulled from database and displayed in textboxes. Everything is working fine. But I need to display the value as No Data Available in those textboxes if(!rs.next()), currently I'm trying the below code.
package org.DAO;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import org.bean.UserBean;
import org.code.general.DBConnection;
import org.code.general.GetTheUserDetails;
public class GetDataDAO {
DBConnection dbConnection = new DBConnection();
GetTheUserDetails getTheUserDetails = new GetTheUserDetails();
public List<UserBean> list(String systemUserName) throws Exception {
List<UserBean> userBeans = new ArrayList<UserBean>();
try {
Connection conn = dbConnection.getConn();
Statement stmt = dbConnection.getStmt();
ResultSet rs = dbConnection.getRs();
String excelPath = dbConnection.getExcelPath();
String queryString = null;
dbConnection.createClassForNameForExcel();
conn = DriverManager.getConnection(
"jdbc:odbc:Driver={Microsoft Excel Driver (*.xls)};DBQ=" + excelPath + "; READONLY=FALSE;");
System.out.println("Connecting to database…");
System.out.println("Oracle JDBC Driver Registered!");
if (conn != null) {
System.out.println("You made it, take control your database now!");
} else {
System.out.println("Failed to make connection!");
}
stmt = conn.createStatement();
queryString = "Select * from [" + dbConnection.getSheetPath()
+ "$] where STATE IS NULL and [Case Owner] = '"
+ getTheUserDetails.getUserNameDetails(systemUserName) + "'";
System.out.println("Query is " + queryString);
rs = stmt.executeQuery(queryString);
ResultSetMetaData rsmd = rs.getMetaData();
System.out.println("bno of cols are " + rsmd.getColumnCount());
while (rs.next()) {
if (rs.next()) {
UserBean userBean = new UserBean();
userBean.setCaseNumber(rs.getString(1));
userBean.setCaseOwner(rs.getString(2));
userBean.setStatus(rs.getString(4));
userBean.setIssue(rs.getString(5));
userBean.setReason(rs.getString(6));
userBean.setDateOpened(rs.getString(7));
userBean.setAge(rs.getInt(8));
userBeans.add(userBean);
} else {
UserBean userBean = new UserBean();
userBean.setCaseNumber("None");
userBean.setCaseOwner("None");
userBean.setStatus("None");
userBean.setIssue("None");
userBean.setReason("None");
userBean.setDateOpened("None");
userBean.setAge(Integer.parseInt("None"));
userBeans.add(userBean);
}
}
rs.close();
conn.commit();
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
return userBeans;
}
}
As per my understanding, I've written trying the below algorithm,
if(rs.next)
then create the bean and add the values from database,
else
create the bean and add the values as None
please let me know where am I going wrong and how can I fix this.
Thanks

if(rs.next)
then create the bean and add the values from database,
else
set the bean as null
In jsp check if bean is null then No Data Available under text boxes. Ideally you should do it in servlet or controller as jsp should be as light as it can be

public boolean next()
Moves the cursor to the next row. This method returns false if there are no more rows in the result set.
So when you call rs.next() twice, once in while and once in if , you will miss one row every time.
Try remove if condition

The code is skipping a row per iteration:
while (rs.next()) {
if (rs.next())
If the result set is either 0 or 1 row then just use rs.next():
if (rs.next())
{
// Use 'rs'.
}
else
{
// "None".
}
Additionally:
the null check on conn is superfluous as DriverManager.getConnection() throws an exception if it fails.
use try-with-resources to ensure Connection, Statement and ResultSet are always released.

You would have to have logic like this, if the rows are empty:
rs = stmt.executeQuery(queryString);
ResultSetMetaData rsmd = rs.getMetaData();
System.out.println("bno of cols are " + rsmd.getColumnCount());
while (rs.next()) {
UserBean userBean = new UserBean();
userBean.setCaseNumber(rs.getString(1));
userBean.setCaseOwner(rs.getString(2));
userBean.setStatus(rs.getString(4));
userBean.setIssue(rs.getString(5));
userBean.setReason(rs.getString(6));
userBean.setDateOpened(rs.getString(7));
userBean.setAge(rs.getInt(8));
userBeans.add(userBean);
}
if(userBeans.size() == 0) {
UserBean userBean = new UserBean();
userBean.setCaseNumber("None");
userBean.setCaseOwner("None");
userBean.setStatus("None");
userBean.setIssue("None");
userBean.setReason("None");
userBean.setDateOpened("None");
userBean.setAge(Integer.parseInt("None"));
userBeans.add(userBean);
}
rs.close();
conn.commit();
conn.close();
But if the rows are not empty, just containing null values, then you can have the logic like this:
rs = stmt.executeQuery(queryString);
ResultSetMetaData rsmd = rs.getMetaData();
System.out.println("bno of cols are " + rsmd.getColumnCount());
while (rs.next()) {
UserBean userBean = new UserBean();
String value = rs.getString(1) == null ? "None" : rs.getString(1);
// you do this for all the columns, from 1 to 8
userBean.setCaseNumber(rs.getString(1));
userBean.setCaseOwner(rs.getString(2));
userBean.setStatus(rs.getString(4));
userBean.setIssue(rs.getString(5));
userBean.setReason(rs.getString(6));
userBean.setDateOpened(rs.getString(7));
userBean.setAge(rs.getInt(8));
userBeans.add(userBean);
}
rs.close();
conn.commit();
conn.close();

Related

How do I use SELECT LAST_INSERT_ID() without closing the connection [duplicate]

I want to INSERT a record in a database (which is Microsoft SQL Server in my case) using JDBC in Java. At the same time, I want to obtain the insert ID. How can I achieve this using JDBC API?
If it is an auto generated key, then you can use Statement#getGeneratedKeys() for this. You need to call it on the same Statement as the one being used for the INSERT. You first need to create the statement using Statement.RETURN_GENERATED_KEYS to notify the JDBC driver to return the keys.
Here's a basic example:
public void create(User user) throws SQLException {
try (
Connection connection = dataSource.getConnection();
PreparedStatement statement = connection.prepareStatement(SQL_INSERT,
Statement.RETURN_GENERATED_KEYS);
) {
statement.setString(1, user.getName());
statement.setString(2, user.getPassword());
statement.setString(3, user.getEmail());
// ...
int affectedRows = statement.executeUpdate();
if (affectedRows == 0) {
throw new SQLException("Creating user failed, no rows affected.");
}
try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
if (generatedKeys.next()) {
user.setId(generatedKeys.getLong(1));
}
else {
throw new SQLException("Creating user failed, no ID obtained.");
}
}
}
}
Note that you're dependent on the JDBC driver as to whether it works. Currently, most of the last versions will work, but if I am correct, Oracle JDBC driver is still somewhat troublesome with this. MySQL and DB2 already supported it for ages. PostgreSQL started to support it not long ago. I can't comment about MSSQL as I've never used it.
For Oracle, you can invoke a CallableStatement with a RETURNING clause or a SELECT CURRVAL(sequencename) (or whatever DB-specific syntax to do so) directly after the INSERT in the same transaction to obtain the last generated key. See also this answer.
Create Generated Column
String generatedColumns[] = { "ID" };
Pass this geneated Column to your statement
PreparedStatement stmtInsert = conn.prepareStatement(insertSQL, generatedColumns);
Use ResultSet object to fetch the GeneratedKeys on Statement
ResultSet rs = stmtInsert.getGeneratedKeys();
if (rs.next()) {
long id = rs.getLong(1);
System.out.println("Inserted ID -" + id); // display inserted record
}
When encountering an 'Unsupported feature' error while using Statement.RETURN_GENERATED_KEYS, try this:
String[] returnId = { "BATCHID" };
String sql = "INSERT INTO BATCH (BATCHNAME) VALUES ('aaaaaaa')";
PreparedStatement statement = connection.prepareStatement(sql, returnId);
int affectedRows = statement.executeUpdate();
if (affectedRows == 0) {
throw new SQLException("Creating user failed, no rows affected.");
}
try (ResultSet rs = statement.getGeneratedKeys()) {
if (rs.next()) {
System.out.println(rs.getInt(1));
}
rs.close();
}
Where BATCHID is the auto generated id.
I'm hitting Microsoft SQL Server 2008 R2 from a single-threaded JDBC-based application and pulling back the last ID without using the RETURN_GENERATED_KEYS property or any PreparedStatement. Looks something like this:
private int insertQueryReturnInt(String SQLQy) {
ResultSet generatedKeys = null;
int generatedKey = -1;
try {
Statement statement = conn.createStatement();
statement.execute(SQLQy);
} catch (Exception e) {
errorDescription = "Failed to insert SQL query: " + SQLQy + "( " + e.toString() + ")";
return -1;
}
try {
generatedKey = Integer.parseInt(readOneValue("SELECT ##IDENTITY"));
} catch (Exception e) {
errorDescription = "Failed to get ID of just-inserted SQL query: " + SQLQy + "( " + e.toString() + ")";
return -1;
}
return generatedKey;
}
This blog post nicely isolates three main SQL Server "last ID" options:
http://msjawahar.wordpress.com/2008/01/25/how-to-find-the-last-identity-value-inserted-in-the-sql-server/ - haven't needed the other two yet.
Instead of a comment, I just want to answer post.
Interface java.sql.PreparedStatement
columnIndexes « You can use prepareStatement function that accepts columnIndexes and SQL statement.
Where columnIndexes allowed constant flags are Statement.RETURN_GENERATED_KEYS1 or Statement.NO_GENERATED_KEYS[2], SQL statement that may contain one or more '?' IN parameter placeholders.
SYNTAX «
Connection.prepareStatement(String sql, int autoGeneratedKeys)
Connection.prepareStatement(String sql, int[] columnIndexes)
Example:
PreparedStatement pstmt =
conn.prepareStatement( insertSQL, Statement.RETURN_GENERATED_KEYS );
columnNames « List out the columnNames like 'id', 'uniqueID', .... in the target table that contain the auto-generated keys that should be returned. The driver will ignore them if the SQL statement is not an INSERT statement.
SYNTAX «
Connection.prepareStatement(String sql, String[] columnNames)
Example:
String columnNames[] = new String[] { "id" };
PreparedStatement pstmt = conn.prepareStatement( insertSQL, columnNames );
Full Example:
public static void insertAutoIncrement_SQL(String UserName, String Language, String Message) {
String DB_URL = "jdbc:mysql://localhost:3306/test", DB_User = "root", DB_Password = "";
String insertSQL = "INSERT INTO `unicodeinfo`( `UserName`, `Language`, `Message`) VALUES (?,?,?)";
//"INSERT INTO `unicodeinfo`(`id`, `UserName`, `Language`, `Message`) VALUES (?,?,?,?)";
int primkey = 0 ;
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection(DB_URL, DB_User, DB_Password);
String columnNames[] = new String[] { "id" };
PreparedStatement pstmt = conn.prepareStatement( insertSQL, columnNames );
pstmt.setString(1, UserName );
pstmt.setString(2, Language );
pstmt.setString(3, Message );
if (pstmt.executeUpdate() > 0) {
// Retrieves any auto-generated keys created as a result of executing this Statement object
java.sql.ResultSet generatedKeys = pstmt.getGeneratedKeys();
if ( generatedKeys.next() ) {
primkey = generatedKeys.getInt(1);
}
}
System.out.println("Record updated with id = "+primkey);
} catch (InstantiationException | IllegalAccessException | ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
I'm using SQLServer 2008, but I have a development limitation: I cannot use a new driver for it, I have to use "com.microsoft.jdbc.sqlserver.SQLServerDriver" (I cannot use "com.microsoft.sqlserver.jdbc.SQLServerDriver").
That's why the solution conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS) threw a java.lang.AbstractMethodError for me.
In this situation, a possible solution I found is the old one suggested by Microsoft:
How To Retrieve ##IDENTITY Value Using JDBC
import java.sql.*;
import java.io.*;
public class IdentitySample
{
public static void main(String args[])
{
try
{
String URL = "jdbc:microsoft:sqlserver://yourServer:1433;databasename=pubs";
String userName = "yourUser";
String password = "yourPassword";
System.out.println( "Trying to connect to: " + URL);
//Register JDBC Driver
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
//Connect to SQL Server
Connection con = null;
con = DriverManager.getConnection(URL,userName,password);
System.out.println("Successfully connected to server");
//Create statement and Execute using either a stored procecure or batch statement
CallableStatement callstmt = null;
callstmt = con.prepareCall("INSERT INTO myIdentTable (col2) VALUES (?);SELECT ##IDENTITY");
callstmt.setString(1, "testInputBatch");
System.out.println("Batch statement successfully executed");
callstmt.execute();
int iUpdCount = callstmt.getUpdateCount();
boolean bMoreResults = true;
ResultSet rs = null;
int myIdentVal = -1; //to store the ##IDENTITY
//While there are still more results or update counts
//available, continue processing resultsets
while (bMoreResults || iUpdCount!=-1)
{
//NOTE: in order for output parameters to be available,
//all resultsets must be processed
rs = callstmt.getResultSet();
//if rs is not null, we know we can get the results from the SELECT ##IDENTITY
if (rs != null)
{
rs.next();
myIdentVal = rs.getInt(1);
}
//Do something with the results here (not shown)
//get the next resultset, if there is one
//this call also implicitly closes the previously obtained ResultSet
bMoreResults = callstmt.getMoreResults();
iUpdCount = callstmt.getUpdateCount();
}
System.out.println( "##IDENTITY is: " + myIdentVal);
//Close statement and connection
callstmt.close();
con.close();
}
catch (Exception ex)
{
ex.printStackTrace();
}
try
{
System.out.println("Press any key to quit...");
System.in.read();
}
catch (Exception e)
{
}
}
}
This solution worked for me!
I hope this helps!
You can use following java code to get new inserted id.
ps = con.prepareStatement(query, Statement.RETURN_GENERATED_KEYS);
ps.setInt(1, quizid);
ps.setInt(2, userid);
ps.executeUpdate();
ResultSet rs = ps.getGeneratedKeys();
if (rs.next()) {
lastInsertId = rs.getInt(1);
}
It is possible to use it with normal Statement's as well (not just PreparedStatement)
Statement statement = conn.createStatement();
int updateCount = statement.executeUpdate("insert into x...)", Statement.RETURN_GENERATED_KEYS);
try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
if (generatedKeys.next()) {
return generatedKeys.getLong(1);
}
else {
throw new SQLException("Creating failed, no ID obtained.");
}
}
Most others have suggested to use JDBC API for this, but personally, I find it quite painful to do with most drivers. When in fact, you can just use a native T-SQL feature, the OUTPUT clause:
try (
Statement s = c.createStatement();
ResultSet rs = s.executeQuery(
"""
INSERT INTO t (a, b)
OUTPUT id
VALUES (1, 2)
"""
);
) {
while (rs.next())
System.out.println("ID = " + rs.getLong(1));
}
This is the simplest solution for SQL Server as well as a few other SQL dialects (e.g. Firebird, MariaDB, PostgreSQL, where you'd use RETURNING instead of OUTPUT).
I've blogged about this topic more in detail here.
With Hibernate's NativeQuery, you need to return a ResultList instead of a SingleResult, because Hibernate modifies a native query
INSERT INTO bla (a,b) VALUES (2,3) RETURNING id
like
INSERT INTO bla (a,b) VALUES (2,3) RETURNING id LIMIT 1
if you try to get a single result, which causes most databases (at least PostgreSQL) to throw a syntax error. Afterwards, you may fetch the resulting id from the list (which usually contains exactly one item).
In my case ->
ConnectionClass objConnectionClass=new ConnectionClass();
con=objConnectionClass.getDataBaseConnection();
pstmtGetAdd=con.prepareStatement(SQL_INSERT_ADDRESS_QUERY,Statement.RETURN_GENERATED_KEYS);
pstmtGetAdd.setString(1, objRegisterVO.getAddress());
pstmtGetAdd.setInt(2, Integer.parseInt(objRegisterVO.getCityId()));
int addId=pstmtGetAdd.executeUpdate();
if(addId>0)
{
ResultSet rsVal=pstmtGetAdd.getGeneratedKeys();
rsVal.next();
addId=rsVal.getInt(1);
}
If you are using Spring JDBC, you can use Spring's GeneratedKeyHolder class to get the inserted ID.
See this answer...
How to get inserted id using Spring Jdbctemplate.update(String sql, obj...args)
If you are using JDBC (tested with MySQL) and you just want the last inserted ID, there is an easy way to get it. The method I'm using is the following:
public static Integer insert(ConnectionImpl connection, String insertQuery){
Integer lastInsertId = -1;
try{
final PreparedStatement ps = connection.prepareStatement(insertQuery);
ps.executeUpdate(insertQuery);
final com.mysql.jdbc.PreparedStatement psFinal = (com.mysql.jdbc.PreparedStatement) ps;
lastInsertId = (int) psFinal.getLastInsertID();
connection.close();
} catch(SQLException ex){
System.err.println("Error: "+ex);
}
return lastInsertId;
}
Also, (and just in case) the method to get the ConnectionImpl is the following:
public static ConnectionImpl getConnectionImpl(){
ConnectionImpl conexion = null;
final String dbName = "database_name";
final String dbPort = "3306";
final String dbIPAddress = "127.0.0.1";
final String connectionPath = "jdbc:mysql://"+dbIPAddress+":"+dbPort+"/"+dbName+"?autoReconnect=true&useSSL=false";
final String dbUser = "database_user";
final String dbPassword = "database_password";
try{
conexion = (ConnectionImpl) DriverManager.getConnection(connectionPath, dbUser, dbPassword);
}catch(SQLException e){
System.err.println(e);
}
return conexion;
}
Remember to add the connector/J to the project referenced libraries.
In my case, the connector/J version is the 5.1.42. Maybe you will have to apply some changes to the connectionPath if you want to use a more modern version of the connector/J such as with the version 8.0.28.
In the file, remember to import the following resources:
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import com.mysql.jdbc.ConnectionImpl;
Hope this will be helpful.
Connection cn = DriverManager.getConnection("Host","user","pass");
Statement st = cn.createStatement("Ur Requet Sql");
int ret = st.execute();

Return a dynamic array based on SQL

I would like to create a method that returns an array with all the values from the database.
This is what I have so far:
package ch.test.zt;
import java.sql.*;
class Database {
static boolean getData(String sql) {
// Ensure we have mariadb Driver in classpath
try {
Class.forName("org.mariadb.jdbc.Driver");
}
catch (ClassNotFoundException e) {
e.printStackTrace();
}
String url = "jdbc:mariadb://localhost:3306/zt_productions?user=root&password=test";
try {
Connection conn = DriverManager.getConnection(url);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
return rs.next();
}
catch (SQLException e) {
e.printStackTrace();
}
return false;
}
}
That means, I could use Database.getData("SELECT * FROM users") and I get an array with all the data from the database that I need.
In my code above I am using return rs.next();, which is definitely wrong. That returns true.
rs.next(); just tell whether your result set has data in it or not i.e true or false , in order to use or create array of the actual data , you have to iterate over your result set and create a user object from it and have to add that object in your users list
Also change the signature
static List<User> getData(String sql)
And best to use like Select Username,UserId from Users; as your sql
something like this:
try { List<User> userList = new ArrayLisy();
Connection conn = DriverManager.getConnection(url);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
//until there are results in the resultset loop over it
while (rs.next()) {
User user = new User();
user.SetName(rs.getString("username"));
// so on.. for other fields like userID ,age , gender ,loginDate,isActive etc ..
userList.add(user);
}
}
when you don't know about the columns of the table you are going to fetch then you can find the same using :
Now you know all the information then you can construct a proper query using it
and work from this
DatabaseMetaData metadata = connection.getMetaData();
ResultSet resultSet = metadata.getColumns(null, null, "users", null);
while (resultSet.next()) {
String name = resultSet.getString("COLUMN_NAME");
String type = resultSet.getString("TYPE_NAME");
int size = resultSet.getInt("COLUMN_SIZE");
System.out.println("Column name: [" + name + "]; type: [" + type + "]; size: [" + size + "]");
}
}

java.sql.SQLException: Column index out range, (int) < 1 [duplicate]

I want to INSERT a record in a database (which is Microsoft SQL Server in my case) using JDBC in Java. At the same time, I want to obtain the insert ID. How can I achieve this using JDBC API?
If it is an auto generated key, then you can use Statement#getGeneratedKeys() for this. You need to call it on the same Statement as the one being used for the INSERT. You first need to create the statement using Statement.RETURN_GENERATED_KEYS to notify the JDBC driver to return the keys.
Here's a basic example:
public void create(User user) throws SQLException {
try (
Connection connection = dataSource.getConnection();
PreparedStatement statement = connection.prepareStatement(SQL_INSERT,
Statement.RETURN_GENERATED_KEYS);
) {
statement.setString(1, user.getName());
statement.setString(2, user.getPassword());
statement.setString(3, user.getEmail());
// ...
int affectedRows = statement.executeUpdate();
if (affectedRows == 0) {
throw new SQLException("Creating user failed, no rows affected.");
}
try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
if (generatedKeys.next()) {
user.setId(generatedKeys.getLong(1));
}
else {
throw new SQLException("Creating user failed, no ID obtained.");
}
}
}
}
Note that you're dependent on the JDBC driver as to whether it works. Currently, most of the last versions will work, but if I am correct, Oracle JDBC driver is still somewhat troublesome with this. MySQL and DB2 already supported it for ages. PostgreSQL started to support it not long ago. I can't comment about MSSQL as I've never used it.
For Oracle, you can invoke a CallableStatement with a RETURNING clause or a SELECT CURRVAL(sequencename) (or whatever DB-specific syntax to do so) directly after the INSERT in the same transaction to obtain the last generated key. See also this answer.
Create Generated Column
String generatedColumns[] = { "ID" };
Pass this geneated Column to your statement
PreparedStatement stmtInsert = conn.prepareStatement(insertSQL, generatedColumns);
Use ResultSet object to fetch the GeneratedKeys on Statement
ResultSet rs = stmtInsert.getGeneratedKeys();
if (rs.next()) {
long id = rs.getLong(1);
System.out.println("Inserted ID -" + id); // display inserted record
}
When encountering an 'Unsupported feature' error while using Statement.RETURN_GENERATED_KEYS, try this:
String[] returnId = { "BATCHID" };
String sql = "INSERT INTO BATCH (BATCHNAME) VALUES ('aaaaaaa')";
PreparedStatement statement = connection.prepareStatement(sql, returnId);
int affectedRows = statement.executeUpdate();
if (affectedRows == 0) {
throw new SQLException("Creating user failed, no rows affected.");
}
try (ResultSet rs = statement.getGeneratedKeys()) {
if (rs.next()) {
System.out.println(rs.getInt(1));
}
rs.close();
}
Where BATCHID is the auto generated id.
I'm hitting Microsoft SQL Server 2008 R2 from a single-threaded JDBC-based application and pulling back the last ID without using the RETURN_GENERATED_KEYS property or any PreparedStatement. Looks something like this:
private int insertQueryReturnInt(String SQLQy) {
ResultSet generatedKeys = null;
int generatedKey = -1;
try {
Statement statement = conn.createStatement();
statement.execute(SQLQy);
} catch (Exception e) {
errorDescription = "Failed to insert SQL query: " + SQLQy + "( " + e.toString() + ")";
return -1;
}
try {
generatedKey = Integer.parseInt(readOneValue("SELECT ##IDENTITY"));
} catch (Exception e) {
errorDescription = "Failed to get ID of just-inserted SQL query: " + SQLQy + "( " + e.toString() + ")";
return -1;
}
return generatedKey;
}
This blog post nicely isolates three main SQL Server "last ID" options:
http://msjawahar.wordpress.com/2008/01/25/how-to-find-the-last-identity-value-inserted-in-the-sql-server/ - haven't needed the other two yet.
Instead of a comment, I just want to answer post.
Interface java.sql.PreparedStatement
columnIndexes « You can use prepareStatement function that accepts columnIndexes and SQL statement.
Where columnIndexes allowed constant flags are Statement.RETURN_GENERATED_KEYS1 or Statement.NO_GENERATED_KEYS[2], SQL statement that may contain one or more '?' IN parameter placeholders.
SYNTAX «
Connection.prepareStatement(String sql, int autoGeneratedKeys)
Connection.prepareStatement(String sql, int[] columnIndexes)
Example:
PreparedStatement pstmt =
conn.prepareStatement( insertSQL, Statement.RETURN_GENERATED_KEYS );
columnNames « List out the columnNames like 'id', 'uniqueID', .... in the target table that contain the auto-generated keys that should be returned. The driver will ignore them if the SQL statement is not an INSERT statement.
SYNTAX «
Connection.prepareStatement(String sql, String[] columnNames)
Example:
String columnNames[] = new String[] { "id" };
PreparedStatement pstmt = conn.prepareStatement( insertSQL, columnNames );
Full Example:
public static void insertAutoIncrement_SQL(String UserName, String Language, String Message) {
String DB_URL = "jdbc:mysql://localhost:3306/test", DB_User = "root", DB_Password = "";
String insertSQL = "INSERT INTO `unicodeinfo`( `UserName`, `Language`, `Message`) VALUES (?,?,?)";
//"INSERT INTO `unicodeinfo`(`id`, `UserName`, `Language`, `Message`) VALUES (?,?,?,?)";
int primkey = 0 ;
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection(DB_URL, DB_User, DB_Password);
String columnNames[] = new String[] { "id" };
PreparedStatement pstmt = conn.prepareStatement( insertSQL, columnNames );
pstmt.setString(1, UserName );
pstmt.setString(2, Language );
pstmt.setString(3, Message );
if (pstmt.executeUpdate() > 0) {
// Retrieves any auto-generated keys created as a result of executing this Statement object
java.sql.ResultSet generatedKeys = pstmt.getGeneratedKeys();
if ( generatedKeys.next() ) {
primkey = generatedKeys.getInt(1);
}
}
System.out.println("Record updated with id = "+primkey);
} catch (InstantiationException | IllegalAccessException | ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
I'm using SQLServer 2008, but I have a development limitation: I cannot use a new driver for it, I have to use "com.microsoft.jdbc.sqlserver.SQLServerDriver" (I cannot use "com.microsoft.sqlserver.jdbc.SQLServerDriver").
That's why the solution conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS) threw a java.lang.AbstractMethodError for me.
In this situation, a possible solution I found is the old one suggested by Microsoft:
How To Retrieve ##IDENTITY Value Using JDBC
import java.sql.*;
import java.io.*;
public class IdentitySample
{
public static void main(String args[])
{
try
{
String URL = "jdbc:microsoft:sqlserver://yourServer:1433;databasename=pubs";
String userName = "yourUser";
String password = "yourPassword";
System.out.println( "Trying to connect to: " + URL);
//Register JDBC Driver
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
//Connect to SQL Server
Connection con = null;
con = DriverManager.getConnection(URL,userName,password);
System.out.println("Successfully connected to server");
//Create statement and Execute using either a stored procecure or batch statement
CallableStatement callstmt = null;
callstmt = con.prepareCall("INSERT INTO myIdentTable (col2) VALUES (?);SELECT ##IDENTITY");
callstmt.setString(1, "testInputBatch");
System.out.println("Batch statement successfully executed");
callstmt.execute();
int iUpdCount = callstmt.getUpdateCount();
boolean bMoreResults = true;
ResultSet rs = null;
int myIdentVal = -1; //to store the ##IDENTITY
//While there are still more results or update counts
//available, continue processing resultsets
while (bMoreResults || iUpdCount!=-1)
{
//NOTE: in order for output parameters to be available,
//all resultsets must be processed
rs = callstmt.getResultSet();
//if rs is not null, we know we can get the results from the SELECT ##IDENTITY
if (rs != null)
{
rs.next();
myIdentVal = rs.getInt(1);
}
//Do something with the results here (not shown)
//get the next resultset, if there is one
//this call also implicitly closes the previously obtained ResultSet
bMoreResults = callstmt.getMoreResults();
iUpdCount = callstmt.getUpdateCount();
}
System.out.println( "##IDENTITY is: " + myIdentVal);
//Close statement and connection
callstmt.close();
con.close();
}
catch (Exception ex)
{
ex.printStackTrace();
}
try
{
System.out.println("Press any key to quit...");
System.in.read();
}
catch (Exception e)
{
}
}
}
This solution worked for me!
I hope this helps!
You can use following java code to get new inserted id.
ps = con.prepareStatement(query, Statement.RETURN_GENERATED_KEYS);
ps.setInt(1, quizid);
ps.setInt(2, userid);
ps.executeUpdate();
ResultSet rs = ps.getGeneratedKeys();
if (rs.next()) {
lastInsertId = rs.getInt(1);
}
It is possible to use it with normal Statement's as well (not just PreparedStatement)
Statement statement = conn.createStatement();
int updateCount = statement.executeUpdate("insert into x...)", Statement.RETURN_GENERATED_KEYS);
try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
if (generatedKeys.next()) {
return generatedKeys.getLong(1);
}
else {
throw new SQLException("Creating failed, no ID obtained.");
}
}
Most others have suggested to use JDBC API for this, but personally, I find it quite painful to do with most drivers. When in fact, you can just use a native T-SQL feature, the OUTPUT clause:
try (
Statement s = c.createStatement();
ResultSet rs = s.executeQuery(
"""
INSERT INTO t (a, b)
OUTPUT id
VALUES (1, 2)
"""
);
) {
while (rs.next())
System.out.println("ID = " + rs.getLong(1));
}
This is the simplest solution for SQL Server as well as a few other SQL dialects (e.g. Firebird, MariaDB, PostgreSQL, where you'd use RETURNING instead of OUTPUT).
I've blogged about this topic more in detail here.
With Hibernate's NativeQuery, you need to return a ResultList instead of a SingleResult, because Hibernate modifies a native query
INSERT INTO bla (a,b) VALUES (2,3) RETURNING id
like
INSERT INTO bla (a,b) VALUES (2,3) RETURNING id LIMIT 1
if you try to get a single result, which causes most databases (at least PostgreSQL) to throw a syntax error. Afterwards, you may fetch the resulting id from the list (which usually contains exactly one item).
In my case ->
ConnectionClass objConnectionClass=new ConnectionClass();
con=objConnectionClass.getDataBaseConnection();
pstmtGetAdd=con.prepareStatement(SQL_INSERT_ADDRESS_QUERY,Statement.RETURN_GENERATED_KEYS);
pstmtGetAdd.setString(1, objRegisterVO.getAddress());
pstmtGetAdd.setInt(2, Integer.parseInt(objRegisterVO.getCityId()));
int addId=pstmtGetAdd.executeUpdate();
if(addId>0)
{
ResultSet rsVal=pstmtGetAdd.getGeneratedKeys();
rsVal.next();
addId=rsVal.getInt(1);
}
If you are using Spring JDBC, you can use Spring's GeneratedKeyHolder class to get the inserted ID.
See this answer...
How to get inserted id using Spring Jdbctemplate.update(String sql, obj...args)
If you are using JDBC (tested with MySQL) and you just want the last inserted ID, there is an easy way to get it. The method I'm using is the following:
public static Integer insert(ConnectionImpl connection, String insertQuery){
Integer lastInsertId = -1;
try{
final PreparedStatement ps = connection.prepareStatement(insertQuery);
ps.executeUpdate(insertQuery);
final com.mysql.jdbc.PreparedStatement psFinal = (com.mysql.jdbc.PreparedStatement) ps;
lastInsertId = (int) psFinal.getLastInsertID();
connection.close();
} catch(SQLException ex){
System.err.println("Error: "+ex);
}
return lastInsertId;
}
Also, (and just in case) the method to get the ConnectionImpl is the following:
public static ConnectionImpl getConnectionImpl(){
ConnectionImpl conexion = null;
final String dbName = "database_name";
final String dbPort = "3306";
final String dbIPAddress = "127.0.0.1";
final String connectionPath = "jdbc:mysql://"+dbIPAddress+":"+dbPort+"/"+dbName+"?autoReconnect=true&useSSL=false";
final String dbUser = "database_user";
final String dbPassword = "database_password";
try{
conexion = (ConnectionImpl) DriverManager.getConnection(connectionPath, dbUser, dbPassword);
}catch(SQLException e){
System.err.println(e);
}
return conexion;
}
Remember to add the connector/J to the project referenced libraries.
In my case, the connector/J version is the 5.1.42. Maybe you will have to apply some changes to the connectionPath if you want to use a more modern version of the connector/J such as with the version 8.0.28.
In the file, remember to import the following resources:
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import com.mysql.jdbc.ConnectionImpl;
Hope this will be helpful.
Connection cn = DriverManager.getConnection("Host","user","pass");
Statement st = cn.createStatement("Ur Requet Sql");
int ret = st.execute();

java loop store database and call it back error

When created random email and store in mysql database its working fine then i try to print that random email but i can't. Anyone help me where can i edit my code?
Without ResultSet rs=statement.executeQuery("select * from user_data"); and
System.out.println(rs.getString(1)); its working fine
note:- someone please edit my grammar
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Random;
public class new_test {
public static void main(String[] args) {
ArrayList<String>objectsToStores = new ArrayList<>();
Random rad = new Random();
for (int j=1; j<=3; j++ )
{
objectsToStores.add("usename"+rad.nextInt()+"#gmail.com");
}
try {
Class.forName("com.mysql.jdbc.Driver") ;
Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test?useSSL=false", "root", "");
connection.setAutoCommit(false);
Statement statement = connection.createStatement();
ResultSet rs=statement.executeQuery("select * from user_data");
for (String x : objectsToStores ) {
statement.executeUpdate("INSERT INTO USER_DATA (email) VALUES ('" +x +"')");
}
while(rs.next())
System.out.println(rs.getString(1));
connection.commit();
statement.close();
connection.close();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}
The problem was the order that you were using for executing queries on the db
I just moved down the line
ResultSet rs = statement.executeQuery("select * from user_data");
after
statement.executeUpdate("INSERT INTO USER_DATA (email) VALUES ('" + x + "')");
This solve the problem because when you execute the UPDATE (second query) the ResultSet from the SELECT
get closed by the statement so you can't iterate it, and give you an error
try {
// This is not needed anymore with the new driver
//Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test?useSSL=false", "root", "");
connection.setAutoCommit(false);
Statement statement = connection.createStatement();
for (String x : objectsToStores) {
statement.executeUpdate("INSERT INTO USER_DATA (email) VALUES ('" + x + "')");
}
// I just moved this line down
ResultSet rs = statement.executeQuery("select * from user_data");
while (rs.next())
System.out.println(rs.getString(1));
connection.commit();
statement.close();
connection.close();
} catch (Exception e) {
throw new RuntimeException(e);
}

class to connect java program to database(which accepts parameters)

I'm trying to write a class that will accept two strings and an int (username and password and score) from a quizgame, which eventually will come from a GUI, at the minute I'm just passing them through from the main, and pass them into a database to be inserted.
I have the JConnector jar file added and am working in Eclipse.
Here is my code
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Statement;
//public
class DbConnect {
private java.sql.Connection con;
private java.sql.Statement st;
private ResultSet rs;
public DbConnect() {
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(
"jdbc:mysql://localhost:3307/nostalgic", "root", "usbw");
st = con.createStatement();
} catch (Exception ex) {
System.out.println("Error is " + ex);
}
}
public void setData(String n, String p, int x) {
try {
String query = "select * from nostalgic";
String query1 = "INSERT INTO nostalgic values (n,p,x)";
PreparedStatement statement3 = con.prepareStatement(query1);
statement3.executeUpdate();
rs = st.executeQuery(query);
System.out.println("records from database");
while (rs.next()) {
String name1 = rs.getString("name");
String pw = rs.getString("password");
int score = rs.getInt("score");
System.out.println("Name : " + name1);
System.out.println("Password : " + pw);
System.out.println("Score : " + score);
}
} catch (Exception ex) {
System.out.println(ex);
}
}
}
The error I get is
Unknown column 'n' in 'field list'
I can directly put a string in like 'john' but that is no use to me in this situation.
Instead of INSERT INTO nostalgic values (n,p,x) you should have
INSERT INTO nostalgic values (?,?,?) and then:
PreparedStatement statement3 = con.prepareStatement(query1);
statement3.setString(1,n);
statement3.setString(2,p);
statement3.setString(3,x);
statement3.executeUpdate();
in
String query1 = "INSERT INTO nostalgic values (n,p,x)";
n,p,x are not being replaced with the values, they are just being considered as some char that's why you get this error
Edit : before statement3.executeUpdate();
String query1 = "INSERT INTO nostalgic values (?,?,?)";
PreparedStatement statement3 = con.prepareStatement(query1);
statement3.setString(1,n);
statement3.setString(2,p);
statement3.setInt(3,x);
Update: you may wonder why Unknown column 'n' in 'field list'?
Because as insert query in sql can have this structure
INSERT INTO table (col1,col2,...) values (`val1`,`val2`,....)
but then values need to be inside `` if hard coded so if there is no `` sign they are considered as column name.
Mick,
the problem is that you don't pass actual parameters to your query when doing statement3.executeUpdate();. Check this link to see how to do it: http://docs.oracle.com/javase/tutorial/jdbc/basics/prepared.html.
You cannot do it like that try this:
Class.forName("com.mysql.jdbc.Driver");
try (Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3307/nostalgic","root","usbw") {
PreparedStatement pr = null;
String query = "INSERT INTO nostalgic VALUES ((?), (?), (?))";
pr = con.prepareStatement(query);
pr.setString(1, n);
pr.setString(2, p);
pr.setString(3, x);
int status = pr.executeUpdate();
}catch (ClassNotFoundException | SQLException e) {
System.out.println(e.getMessage());
}
There are some mistakes in your code...
Correct imports
Insert statement
Your code will be like that:
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Connection;
import java.jdbc.Statement;
// you imported sql innecessary statements...
//public
class DbConnect {
// dont need complete path, you already imported it
private Connection con;
private Statement st;
private ResultSet rs;
public DbConnect() {
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(
"jdbc:mysql://localhost:3307/nostalgic", "root", "usbw");
st = con.createStatement();
} catch (Exception ex) {
System.out.println("Error is " + ex);
}
}
public void setData(String n, String p, int x) {
try {
String query = "select * from nostalgic";
String query1 = "INSERT INTO nostalgic values (?,?,?)";
// no need to define vars here,
// just number of places to be inserted here ----^
PreparedStatement statement = con.prepareStatement(query1);
// prepare statement
statement = con.prepareStatement(query);
// insert the variables in places you prepared before
// and matching the types you need!!!
statement.setString(1,n);
statement.setString(2,p);
statement.setInt(3,x);
rs = st.executeQuery(query);
System.out.println("records from database");
while (rs.next()) {
String name1 = rs.getString("name");
String pw = rs.getString("password");
int score = rs.getInt("score");
System.out.println("Name : " + name1);
System.out.println("Password : " + pw);
System.out.println("Score : " + score);
}
} catch (Exception ex) {
System.out.println(ex);
}
}
}

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