Using java to read data from MySQL database
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Java
First, I'm using jtextfields to read the user's product name and product quantity For this product, I use SQL query to read the product ID and price from the database But in the following code, I display the product price in jtextfield, but when I run the tha file, I successfully execute the query, but I don't get anything in jtextfield
Please check the use of SQL query and result set. The table name is "item", the database name is "myshop", and I declare variables globally. This code is in the 'actionformed' part of JButton
String item_name=name.getText();
int item_no=Integer.parseInt(no.getText());
String sql="SELECT id,price FROM item WHERE item.name='item_name'";
try{
Class.forName("com.MysqL.jdbc.Driver");
Connection con(Connection)DriverManager.getConnection("jdbc:MysqL://localhost:3306/myshop","root","MysqL");
java.sql.Statement stmt=con.createStatement();
if (stmt.execute(sql)) {
rs = stmt.getResultSet();
JOptionPane.showMessageDialog(this,"succes","executed query",JOptionPane.PLAIN_MESSAGE);
} else {
System.err.println("select Failed");}
int idIndex = rs.findColumn("id");
int priceIndex = rs.findColumn("price");
while(rs.next()){
item_id=rs.getInt(idIndex);
item_price=rs.getInt(priceIndex);
jTextField1.setText(""+item_price);//displaying product price in a jTextField1
jTextField2.setText(""+item_id);//displaying product id in a jTextField2
}
}
catch(Exception e){
JOptionPane.showMessageDialog(this,e.getMessage());
}
Solution
You need to add item_ Name as a parameter and in quotation marks,
String sql="SELECT id,price FROM item WHERE item.name='"+ item_name+"'";
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