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Articles on Trending Technologies
Technical articles with clear explanations and examples
Returning multiple values from a function using Tuple and Pair in C++
In C or C++, we cannot return more than one value from a function. To return multiple values, we have to provide output parameter with the function. Here we will see another approach to return multiple value from a function using tuple and pair STL in C++.The Tuple is an object capable to hold a collection of elements, where each element can be of different types.The pair can make a set of two values, which may be of different types. The pair is basically a special type of tuple, where only two values are allowed.Let us see one example, where ...
Read MoreHow to disable auto resizing for a JTable in Java?
To disable auto resizing for a table in Java, set the setAutoResizeMode() to AUTO_RESIZE_OFF −JTable table = new JTable(tableModel); table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);The following is an example to disable auto resizing for a JTable in Java −package my; import java.awt.Dimension; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JRootPane; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.table.DefaultTableModel; public class SwingDemo { public static void main(String[] argv) throws Exception { JFrame frame = new JFrame("Demo"); JPanel panel = new JPanel(); String data[][] = { {"Australia", "5", "1"}, {"US", "10", "2"}, {"Canada", ...
Read MoreJava Program to retrieve the value from a cell in a JTable
To retrieve the value of a cell, use the getValueAt() method. As parameters, set the row and column index value for which you want the cell value −int rIndex = 5; // row index int cIndex = 1; // column index Object ob = table.getValueAt(rIndex, cIndex);Display the cell value in the Console −System.out.println("Value = "+ob);The following is an example to retrieve the value from a cell −Examplepackage my; import java.awt.Dimension; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JRootPane; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.table.DefaultTableModel; public class SwingDemo { public static void main(String[] argv) throws Exception { JFrame frame ...
Read MoreHow to get primary key value (auto-generated keys) from inserted queries using JDBC?
If you insert records into a table which contains auto-incremented column, using a Statement or, PreparedStatement objects.You can retrieve the values of that particular column, generated by them object using the getGeneratedKeys() method.ExampleLet us create a table with name sales in MySQL database, with one of the columns as auto-incremented, using CREATE statement as shown below −CREATE TABLE Sales( ID INT PRIMARY KEY AUTO_INCREMENT, ProductName VARCHAR (20), CustomerName VARCHAR (20), DispatchDate date, DeliveryTime time, Price INT, Location VARCHAR(20) );Retrieving auto-generated values (PreparedStatement object)Following JDBC program inserts 3 records into the Sales table (created above) ...
Read MoreOrder by on a specific number in MySQL?
Let us first create a table −mysql> create table DemoTable -> ( -> status int -> ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(30); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(30); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.14 sec) ...
Read MoreSimulating final class in C++
In Java or C#, we can use final classes. The final classes are special type of class. We cannot extend that class to create another class. In C++ there are no such direct way. Here we will see how to simulate the final class in C++.Here we will create one extra class called MakeFinalClass (its default constructor is private). This function is used to solve our purpose. The main Class MyClass can call the constructor of the MakeFinalClass as they are friend classes.One thing we have to notice, that the MakeFinalClass is also a virtual base class. We will make ...
Read MoreHow to retrieve a record from an existing table in oracle database using JDBC API?
You can update/modify the existing contents of a record in a table using the UPDATE query. Using this you can update all the records of the table or specific records.SyntaxUPDATE table_name SET column1 = value1, column2 = value2...., columnN = valueN WHERE [condition];To update the contents of a record in a table using JDBC API you need to −Register the Driver: Register the driver class using the registerDriver() method of the DriverManager class. Pass the driver class name to it, as parameter.Establish a connection: Connect to the database using the getConnection() method of the DriverManager class. Passing URL (String), username (String), password (String) ...
Read MoreHow to retrieve the value from a table cell with TableModel in Java?
At first, create a table with DefaultTableModel −String data[][] = { {"Australia", "5", "1"}, {"US", "10", "2"}, {"Canada", "9", "3"}, {"India", "7", "4"}, {"Poland", "2", "5"}, {"SriLanka", "5", "6"} }; String col [] = {"Team", "Selected Players", "Rank"}; DefaultTableModel tableModel = new DefaultTableModel(data, col); JTable table = new JTable(tableModel);Now, use the getModel() to retrieve the value from table cell −Object ob = table.getModel().getValueAt(3, 2); System.out.println("Value = "+ob);The following is an example to retrieve the value from a table cell with TableModel −Examplepackage my; import java.awt.Dimension; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JRootPane; import javax.swing.JScrollPane; import ...
Read MoreRetrieve from MySQL only if it contains two hyphen symbols?
For this, use the LIKE operator. Let us first create a table:mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Password varchar(100) ); Query OK, 0 rows affected (1.27 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Password) values('John@--123'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable(Password) values('---Carol234'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Password) values('--David987'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(Password) values('Mike----53443'); Query OK, 1 row affected (0.30 sec)Display all records from the table using select ...
Read MoreHow to encrypt a CLOB datatype in JDBC?
Creating an Encrypted LOB(CLOB or, BLOB)Oracle database from 11g onwards provides SecureFiles feature to encrypt the Large object files (LOBs). You can create a secure file using the SECUREFILE keyword as −CREATE TABLE table_name ( myClob CLOB ) LOB(myClob) STORE AS SECUREFILE;You can encrypt a secured file using Encrypt option for encryption you can use 3DES168 or, AES128 or, AES192 or, AES256 algorithm.CREATE TABLE encrypt_tab ( myClob CLOB ) LOB(myClob) STORE AS SECUREFILE encrypt_lob( ENCRYPT USING 'AES256' );
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