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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to get column count in a ResultSet in JDBC?
You can get the column count in a table using the getColumnCount() method of the ResultSetMetaData interface. On invoking, this method returns an integer representing the number of columns in the table in the current ResultSet object.//Retrieving the ResultSetMetaData object ResultSetMetaData rsmd = rs.getMetaData(); //getting the column type int column_count = rsmd.getColumnCount();Let us create a table with name employee_data in MySQL database using CREATE statement as shown below −CREATE TABLE employee_data( id INT, Name VARCHAR(255), DOB date, Location VARCHAR(40) );Following JDBC program establishes connection with the database, retrieves the ResultSetMetaData object of the employee_data table, and prints the number of columns in it.Exampleimport ...
Read MoreHow to create and set an Empty Border from BorderFactory class in Java?
To create and set empty border to a component, use the BorderFactory class createEmptyBorder() method −EmptyBorder emptyBorder = (EmptyBorder) BorderFactory.createEmptyBorder();To set the above border to a component, use the setBorder() method −JButton button = new JButton("Empty Border"); button.setBorder(emptyBorder);The following is an example to create and set and empty border from BorderFactory class −package my; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Container; import javax.swing.BorderFactory; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.border.Border; import javax.swing.border.EmptyBorder; import javax.swing.border.SoftBevelBorder; public class SwingDemo { public static void main(String args[]) { JFrame frame = new JFrame("Demo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); ...
Read MoreHow to prevent displaying any grid lines in a JTable?
Let’s say the following is our table −String[][] rec = { { "1", "Steve", "AUS" }, { "2", "Virat", "IND" }, { "3", "Kane", "NZ" }, { "4", "David", "AUS" }, { "5", "Ben", "ENG" }, { "6", "Eion", "ENG" }, }; String[] header = { "Rank", "Player", "Country" }; JTable table = new JTable(rec, header);Prevent displaying grid lines −table.setShowGrid(false);The following is an example to prevent displaying grid lines −Examplepackage my; import java.awt.Color; import javax.swing.BorderFactory; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.border.TitledBorder; public class SwingDemo { public static void main(String[] ...
Read MoreFind the greatest value among four tables in MySQL?
To find the greatest value among four tables, you can use the method GREATEST(). Following is the query to create first table −mysql> create table DemoTable1 -> ( -> Value int -> ); Query OK, 0 rows affected (0.70 sec)Insert some records in the first table using insert command −mysql> insert into DemoTable1 values(10); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1 values(60); Query OK, 1 row affected (0.14 sec)Display all records from the first table using select statement −mysql> select *from DemoTable1;Output+-------+ | Value | +-------+ | 10 | ...
Read MoreHow to get the row count from ResultSet in JDBC
Whenever we execute SQL statements using the executeQuery() method, it returns a ResultSet object which holds the tabular data returned by the SELECT queries(in general). The ResultSet object contains a cursor/pointer which points to the current row. Initially this cursor is positioned before first row (default position).The ResultSet interface provides various methods to find, the no.of columns, name of the column, type of the column etc.. but, it does not provides any method to find the number of rows in a table directly.Using count(*) function in the SELECT query you can get the number of rows in a table as −select ...
Read MoreHow to apply adjustments to the last column of a JTable only, when the width of any column is changed in Java Swing?
To apply adjustments to the last column only, use the setAutoResizeMode and set the mode. The mode here would be AUTO_RESIZE_LAST_COLUMN. This will allow you to adjust only the last columns even if any of the column header is dragged to resize.Let us first see an example to create a table in Java −Examplepackage my; import java.awt.Color; import java.awt.Font; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.table.DefaultTableModel; public class SwingDemo { public static void main(String[] argv) throws Exception { DefaultTableModel tableModel = new DefaultTableModel(); JTable table = new JTable(tableModel); tableModel.addColumn("Technology"); ...
Read MoreHow to get Row and Column Count from ResultSet in JDBC
Row countThe last() method of the ResultSet interface moves the cursor to the last row of the ResultSet and, the getRow() method returns the index/position of the current row.Therefore, to get the number of rows move the cursor to the last row using the last() method and get the position of that (last) row using the getRow() method.Let us create a table with name MyPlayers in MySQL database using CREATE statement as shown below −CREATE TABLE MyPlayers( ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Date_Of_Birth date, Place_Of_Birth VARCHAR(255), Country VARCHAR(255), PRIMARY KEY (ID) );Now, we will insert 7 records in ...
Read MoreHow to set a MatteBorder from BorderFactory in Java?
Set a MatteBorder from BorderFactory class −MatteBorder border = (MatteBorder)BorderFactory.createMatteBorder(2, -1, 5, 10, icon);Now, set the above created MatteBorder to a component −JButton button = new JButton("Matte Border"); button.setBorder(border);The following is an example to set a MatteBorder from BorderFactory class −Examplepackage my; import java.awt.BorderLayout; import java.awt.Container; import javax.swing.BorderFactory; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.border.Border; import javax.swing.border.EtchedBorder; import javax.swing.border.MatteBorder; public class SwingDemo { public static void main(String args[]) { JFrame frame = new JFrame("Demo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Border raisedBorder = new EtchedBorder(EtchedBorder.RAISED); ImageIcon icon = new ImageIcon("new.gif"); ...
Read MoreMySQL query to update every alternative row string having same values?
Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Subject varchar(100) -> ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Subject) values('C'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(Subject) values('MongoDB'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable(Subject) values('Java'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(Subject) values('MongoDB'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Subject) ...
Read MoreHow to generate multiple insert queries via java?
JDBC provides a mechanism known as batch processing, in which you can group a set of INSERT or, UPDATE or, DELETE commands (those produce update count value) and execute them at once. You can insert multiple records in to a table using this.Adding statements to the batchStatement, PreparedStatement and CallableStatement objects hold a list (of commands) to which you can add related statements (those return update count value) using the addBatch() method.stmt.addBatch(insert1); stmt.addBatch(insert2); stmt.addBatch(insert3);Executing the batchAfter adding the required statements, you can execute a batch using the executeBatch() method of the Statement interface.stmt.executeBatch();Using batch updates, we can reduce the communication ...
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