using resultset for updating table - java

I'm trying to update a column of a table from the continuous of another column in the same table after having treated.
I used Java to do the treatment and I only managed to perform this task for the first line of my table.
I do not know why I am unable to browse the "result set". How can I fix this?
String Sql = "Select Update_Action,id_incident from incident where Status like'Closed'";
con = getConnection("jdbc:mysql://localhost:3306/base_rapport","root","");
stmt = con.createStatement();
rs = stmt.executeQuery(Sql);
//treatement
int i = 1;
while(rs.absolute(i))
{
str = rs.getString(1);
nom = "";
while(!"".equals(str))
{
int debut = str.indexOf('(') + 1;
int fin = str.indexOf(')', debut);
nom += " " + str.substring(debut, fin);
str = str.substring(fin + 1, str.length());
nom += ", ";
//updating my table
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/base_rapport", "root", "");
String query = "update incident set intervenants = ? where id_incident=?";
java.sql.PreparedStatement preparedStmt = conn.prepareStatement(query);
preparedStmt.setString(1, nom);
preparedStmt.setString(2, rs.getString(2));
preparedStmt.executeUpdate();
}
//for pointing on the next row of "resultset"
i++;
}

Related

How to concatenate Resultset to String variable

I want to get my ItemName columns value to one String separate from commas.
I tried like this.but its not working
String sql = "SELECT `ItemName` FROM `invoicelist` WHERE `InvoiceId` = '"+invoicenum+"' ";
try {
ResultSet rs = CODE.DbAccess.getdata(sql);
while (rs.next()) {
String em = rs.getString("ItemName");
description = em.replace("\n", ",");
System.out.println(description);
}
You should change to this, if you want to do the concatenation in java:
String sql = "SELECT `ItemName` FROM `invoicelist` WHERE `InvoiceId` = '" + invoicenum + "' ";
try {
ResultSet rs = CODE.DbAccess.getdata(sql);
while (rs.next()) {
description += rs.getString("ItemName") + ",";
}
description = description.substring(0, description.length() - 1);
//System.out.println(description);
}
If you want to concatenate in query then you could search for GROUP_CONCAT() function
String sql = "SELECT `ItemName` FROM `invoicelist` WHERE `InvoiceId` = '" + invoicenum + "' ";
try {
ResultSet rs = CODE.DbAccess.getdata(sql);
StringBuilder builder = new StringBuilder(); // used to store string and append data further if you want
while (rs.next()) {
builder.append(rs.getString("ItemName").append(","); // adding data/Item name to builder and appending comma after adding item name
}
if(builder.length() > 0){ // if there's some data inside builder
builder.setLength(builder.length() - 1); // remove last appended comma from builder
}
System.out.println("Command Separated Data" + builder.toString()); // final data of item name
}
Other way is to concate result from SQL itself.(here's a MySQL compatible code)
String sql = "SELECT group_concat(`ItemName`) as items FROM `invoicelist` WHERE `InvoiceId` = '" + invoicenum + "' ";
try {
ResultSet rs = CODE.DbAccess.getdata(sql);
String data = "";
while (rs.next()) {
data = rs.getString("items")
}
System.out.println("Command Separated Data" + data);
}

Dynamic column name for update query

I'am trying to update table from multiple columns names(lo1,lo2,...) that are to be taken dynamically. But the values are not getting updated in database.
column names are co1,co2....
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
Connection conn = null;
PreparedStatement pstmt = null;
try{
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost/netbeans","root","");
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery("SELECT * FROM colo");
rs = st.executeQuery("SELECT COUNT(*) FROM colo");
// get the number of rows from the result set
rs.next();
int rowCount = rs.getInt(1);
//txt_ans.setText(String.valueOf(rowCount));
int num_1 =300;
int num_2 =200;
int num_3 =300;
int num_4 =400;
String value = null;
int value1 ;
for(int i=1;i<=rowCount;i++)
{
String sql =("SELECT * FROM colo WHERE id = '"+i+"'");
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery(sql);
while(rs.next())
value = rs.getString("co1");
//txt_ans.setText(String.valueOf(value));
String x = "co2";
if(value.equals("lo1"))
{
// value1= 1;
// txt_ans.setText(String.valueOf(value1));
String sql1 =("update colo set '"+x+"' = '"+num_1+"' where id = '"+i+"'");
pstmt = conn.prepareStatement(sql1);
int r = pstmt.executeUpdate(sql1);
txt_ans.setText(String.valueOf(r));
}
else if(value.equals("lo2"))
{
// value1= 1;
// txt_ans.setText(String.valueOf(value1));
String sql1 =("update colo set '"+ x +"' = '"+num_2+"' where id = '"+i+"'");
pstmt = conn.prepareStatement(sql1);
int r = pstmt.executeUpdate(sql1);
txt_ans.setText(String.valueOf(r));
}
else
{
value1 = 9009;
txt_ans.setText(String.valueOf(value1));
}
}
The problem is with using single quotes for column name i.e, like 'x', so just remove them as shown below:
String sql1 =("update colo set " + x + " = ? where id = ?");//no single quote for x
pstmt = conn.prepareStatement(sql1);
pstmt.setString(1, num_1);
pstmt.setString(2, i);
int r = pstmt.executeUpdate(sql1);
Also, always use prepareStatement's setString, etc.. methods for setting the values which is recommended.
Apply the same concept for the other query inside the else if(value.equals("lo2")) block as well.

Verify if the row is not available in mySQL table

I want message (the row is not available in the stock) if row is not available in the database. I try the following code but the error....!
//Code
try {
Connection con = Database.mySqlCon();
String sql = "SELECT count(*) FROM stock WHERE idProduct =?";
PreparedStatement ps = con.prepareStatement(sql);
ResultSet rs = ps.executeQuery();
int count = 0;
while (rs.next()){
count = count + 1;
}
if (count == 1) {
JOptionPane.showMessageDialog(null, "Item is available in Stock"
} else {
JOptionPane.showMessageDialog(null, "ID:" + txtS.getText() + "is not available in the Stock please update the Stock");
}
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
e.printStackTrace();
}
// error....
java.sql.SQLException: No value specified for parameter 1
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:896)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:885)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)
.....
.....
....
....
Please help.....
You are not setting the value for the ? in your SELECT statement.
Given that it's an ID I will assume it is an int.
You need:
Connection con = Database.mySqlCon();
String sql = "SELECT count(*) FROM stock WHERE idProduct =?";
PreparedStatement ps = con.prepareStatement(sql);
ps.setInt(1, value);
ResultSet rs = ps.executeQuery();
EDIT
Try changing your methodology to this:
Connection con = Database.mySqlCon();
String sql = "SELECT count(*) FROM stock WHERE idProduct =?";
PreparedStatement ps = con.prepareStatement(sql);
ps.setInt(1, value);
ResultSet rs = ps.executeQuery();
if(rs.next()){
JOptionPane.showMessageDialog(null, "Item is available in Stock"
}
else {
JOptionPane.showMessageDialog(null, "ID:" + txtS.getText() + "is not available in the Stock please update the Stock");
}
Thanks # Matt for help
i got a perfect Answer by using this code......
try {
Connection con = Database.mySqlCon();
String sql = "SELECT count(*) FROM stock WHERE idProduct =?";
PreparedStatement ps = con.prepareStatement(sql);
ps.setString(1, txtS.getText());
ResultSet rs = ps.executeQuery();
int count = 0;
while (rs.next()){
// code update here
count = rs.getInt(1);
// count = count + 1;
}
if (count == 1) {

PostgreSQL MAX aggregate function applied to strings and Java resultset

Hello and thank you for reading my post.
I have a PostgreSQL table "t" with a column "c" which type is "character varying(32)".
Values in this column look like this: "2014100605".
I am using the "MAX()" aggregate function to retrieve the maximum value in this column.
SELECT MAX(c) AS max FROM t;
In Java, if I prepare the query above, get a "resultSet" object and send it the getString("max") message, I get max = null.
If I send it the getInt("max") method instead, I get the result I'm expecting, something like "2014100605".
Is this normal behavior?
Am I really allowed to do this or is it by chance I'm getting the expected result?
Is "MAX()" actually using the lexicographical order?
Best regards.
A bit of Java code:
s_preparedSqlQuery =
"SELECT MAX(quotinv_nro) AS quotinv_nro_max "
+ "FROM imw_quotation_invoice "
+ "WHERE quotinv_type = ? "
+ "AND quotinv_nro LIKE '" + s_quotinvDate + "%'";
preparedStatement = m_connection.prepareStatement(s_preparedSqlQuery);
preparedStatement.setString(1, s_quotinvType);
resultSet = preparedStatement.executeQuery();
if(resultSet != null)
{
if(resultSet.next())
{
// s_quotinvNroMax = resultSet.getString("quotinv_nro_max");
n_quotinvNroMax = resultSet.getInt("quotinv_nro_max");
// if(s_quotinvNroMax == null)
if(n_quotinvNroMax == 0)
{
n_nbQuotinvsThisSameDate = 0;
return n_nbQuotinvsThisSameDate;
}
else
{
s_quotinvNroMax = Integer.toString(n_quotinvNroMax);
n_length = s_quotinvDate.length();
s_currentMaxNro = s_quotinvNroMax.substring(n_length - 1);
n_nbQuotinvsThisSameDate = Integer.valueOf(s_currentMaxNro);
}
}
}
If you are hitting on a unique Id column....
int maxID = 0;
Statement s2 = con.createStatement();
s2.execute("SELECT MAX(UniqueId) FROM MyTable");
ResultSet rs2 = s2.getResultSet();
if (rs2.next())
{
maxID = rs2.getInt(1);
}
If you are hitting on any other non-key column....
int maxID = 0;
Statement s2 = con.createStatement();
s2.execute("SELECT MAX(ColumnValue) FROM MyTable");
ResultSet rs2 = s2.getResultSet();
while (rs2.next())
{
maxID = rs2.getInt(1);
}

adding the values from gui to the database table

I am trying to update a table in the database where i m accepting fees from the students and maintaining the record of the amount received, total amount received, and the mode of payment etc.
my code is as follows:
private void pay_saveActionPerformed(java.awt.event.ActionEvent evt) {
String dbUrl = "jdbc:mysql://localhost/hostel";
String dbClass = "com.mysql.jdbc.Driver";
PreparedStatement ps1 = null;
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection (dbUrl,"root","17121990");
System.out.println("connected!");
String firstname=pay_enter_firstname.getText();
String lastname=pay_enter_lastname.getText();
String amt=pay_enter_amt.getText();
int amount=Integer.parseInt(amt);
String day=pay_enter_date.getText();
String cheque_no=pay_enter_chequeno.getText();
String mode=pay_enter_mode.getText();
int totalamount=10000;
int bal_amt=totalamount-amount;
String remark=pay_enter_remark.getText();
int id = Integer.parseInt(pay_enter_id.getText());
Statement stmt = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet rs = stmt.executeQuery("SELECT id, lastamtreceived FROM payment");
if(rs.next())
{
stmt = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
rs = stmt.executeQuery("SELECT id, lastamtreceived FROM payment");
while(rs.next())
{
int temp =rs.getInt(1);
if (temp ==id)
{
int amtrecvd2= rs.getInt(2);
bal_amt=totalamount- (amtrecvd2+amount);
String updt = "UPDATE payment SET Amountreceivd="+(amtrecvd2+amount)+",lastamtreceived="+amount+",dte='"+day+"', balance_amt ="+bal_amt+" WHERE id ="+temp+";" ;
Statement stmt1 = con.createStatement();
int result = stmt1.executeUpdate(updt);
}
}
}
if(!rs.next())
{
String str=" INSERT INTO payment(id, firstname,lastname,Amountreceivd,dte,lastamtreceived,Creditcashcheque,"
+ "cheque_no,balance_amt,totalamount,Remark) VALUES ("+id+",'"+firstname+"','"+lastname+"',"+amount+",'"+day+"',"+amount+",'"+mode+"','"+cheque_no+"',"+ bal_amt+","+totalamount+",'"+remark+"')";
Statement stmt1=con.createStatement();
int result=stmt1.executeUpdate(str);
panel_feesframe.setVisible(false);
}
panel_feesframe.setVisible(false);
con.close();
}
catch (ClassNotFoundException | SQLException | NumberFormatException e)
{
e.printStackTrace();
}
}
Initially when i add new values i get it properly but when i am trying to update an existing row i get the error that i m making a duplicate entry for primary key id.
what condition should i check so that i come to know that the result set is not having that particular id value and new person is paying the fee??
This condition:
if(!rs.next())
is being checked outside the while loop. This condition is always true and will try to insert a record even if update has taken place.
To avoid this, i suggest using a flag variable. Once an update has occurred, set the value of this flag to 1.
Check if it has been made 1 instead of if(!rs.next()) and go inside.
You're two if statements are colliding...
// If this is true...
if(rs.next()) {
// ...
// Looping till the it's false...
while(rs.next()) {
// ....
}
}
// Will mean that this is false...
if(!rs.next())
You should be using an else
if(rs.next()) {
// ...
while(rs.next()) {
// ....
}
} else {...}
Updated
After an enlightening conversion with Aashray (thanks), we've concluded that your logic is broken
Rather then manually trying to find the record manually by match the id's let the SQL database do it for you.
Instead of....
ResultSet rs = stmt.executeQuery("SELECT id, lastamtreceived FROM payment");
You should be using...
ResultSet rs = stmt.executeQuery("SELECT id, lastamtreceived FROM payment where id = " + id);
This will return a ResultSet that is either empty (no matches) or with (hopefully) one row.
From there, calling rs.next() will now let you branch of between an update or insert correctly.
private void pay_saveActionPerformed(java.awt.event.ActionEvent evt) {
String dbUrl = "jdbc:mysql://localhost/hostel";
String dbClass = "com.mysql.jdbc.Driver";
PreparedStatement ps1 = null;
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(dbUrl, "root", "17121990");
System.out.println("connected!");
String firstname = pay_enter_firstname.getText();
String lastname = pay_enter_lastname.getText();
String amt = pay_enter_amt.getText();
int amount = Integer.parseInt(amt);
String day = pay_enter_date.getText();
String cheque_no = pay_enter_chequeno.getText();
String mode = pay_enter_mode.getText();
int totalamount = 10000;
int bal_amt = totalamount - amount;
String remark = pay_enter_remark.getText();
int id = Integer.parseInt(pay_enter_id.getText());
Statement stmt = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet rs = stmt.executeQuery("SELECT id, lastamtreceived FROM payment where id = " + id);
if (rs.next()) {
int amtrecvd2 = rs.getInt(2);
bal_amt = totalamount - (amtrecvd2 + amount);
String updt = "UPDATE payment SET Amountreceivd=" + (amtrecvd2 + amount) + ",lastamtreceived=" + amount + ",dte='" + day + "', balance_amt =" + bal_amt + " WHERE id =" + id + ";";
Statement stmt1 = con.createStatement();
int result = stmt1.executeUpdate(updt);
} else {
String str = " INSERT INTO payment(id, firstname,lastname,Amountreceivd,dte,lastamtreceived,Creditcashcheque,"
+ "cheque_no,balance_amt,totalamount,Remark) VALUES (" + id + ",'" + firstname + "','" + lastname + "'," + amount + ",'" + day + "'," + amount + ",'" + mode + "','" + cheque_no + "'," + bal_amt + "," + totalamount + ",'" + remark + "')";
Statement stmt1 = con.createStatement();
int result = stmt1.executeUpdate(str);
panel_feesframe.setVisible(false);
}
panel_feesframe.setVisible(false);
con.close();
} catch (ClassNotFoundException | SQLException | NumberFormatException e) {
e.printStackTrace();
}
}
I think this may help you
private void pay_saveActionPerformed(java.awt.event.ActionEvent evt) {
String dbUrl = "jdbc:mysql://localhost/hostel";
String dbClass = "com.mysql.jdbc.Driver";
PreparedStatement ps1 = null;
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection (dbUrl,"root","17121990");
System.out.println("connected!");
String firstname=pay_enter_firstname.getText();
String lastname=pay_enter_lastname.getText();
String amt=pay_enter_amt.getText();
int amount=Integer.parseInt(amt);
String day=pay_enter_date.getText();
String cheque_no=pay_enter_chequeno.getText();
String mode=pay_enter_mode.getText();
int totalamount=10000;
int bal_amt=totalamount-amount;
String remark=pay_enter_remark.getText();
int id = Integer.parseInt(pay_enter_id.getText());
Statement stmt = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet rs = stmt.executeQuery("SELECT id, lastamtreceived FROM payment");
if(rs.next())
{
stmt = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
rs = stmt.executeQuery("SELECT id, lastamtreceived FROM payment");
while(rs.next())
{
int temp =rs.getInt(1);
if (temp ==id)
{
int amtrecvd2= rs.getInt(2);
bal_amt=totalamount- (amtrecvd2+amount);
String updt = "UPDATE payment SET Amountreceivd="+(amtrecvd2+amount)+",lastamtreceived="+amount+",dte='"+day+"', balance_amt ="+bal_amt+" WHERE id ="+temp+";" ;
Statement stmt1 = con.createStatement();
int result = stmt1.executeUpdate(updt);
}
}
}
else
{
String str=" INSERT INTO payment(id, firstname,lastname,Amountreceivd,dte,lastamtreceived,Creditcashcheque,"
+ "cheque_no,balance_amt,totalamount,Remark) VALUES ("+id+",'"+firstname+"','"+lastname+"',"+amount+",'"+day+"',"+amount+",'"+mode+"','"+cheque_no+"',"+ bal_amt+","+totalamount+",'"+remark+"')";
Statement stmt1=con.createStatement();
int result=stmt1.executeUpdate(str);
panel_feesframe.setVisible(false);
}
panel_feesframe.setVisible(false);
con.close();
}
catch (ClassNotFoundException | SQLException | NumberFormatException e)
{
e.printStackTrace();
}

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