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To make JTree editable in Java, use the TreeCellEditor class. With that, set the setEditable() method to true −TreeCellEditor editor = new DefaultCellEditor(textField); tree.setEditable(true); tree.setCellEditor(editor);The above will make the tree editable. The following is an example to make a JTree editable in Java −Examplepackage my; import javax.swing.DefaultCellEditor; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.TreeCellEditor; public class SwingDemo { public static void main(String[] args) throws Exception { JFrame frame = new JFrame("Demo"); DefaultMutableTreeNode node = new DefaultMutableTreeNode("Products"); DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("Clothing"); DefaultMutableTreeNode node2 = ... Read More
For this, use aggregate framework with the $elemMatch operator. Let us first create a collection with documents −> db.matchMultipleCriteriaDemo.insertOne({ "EmployeeDetails": [ {"EmployeeName": "Chris", "Salary": 45000, "Language":"Java"}, {"EmployeeName": "Robert", "Salary": 41000, "Language":"Python"} ] }); { "acknowledged" : true, "insertedId" : ObjectId("5cea3bf0ef71edecf6a1f689") } > db.matchMultipleCriteriaDemo.insertOne({ "EmployeeDetails": [ {"EmployeeName": "David", "Salary": 55000, "Language":"C++"}, {"EmployeeName": "Bob", "Salary": 61000, "Language":"C"} ] }); { "acknowledged" : true, "insertedId" : ObjectId("5cea3bf1ef71edecf6a1f68a") }Following is the query to display all documents from a collection with the help of find() ... Read More
For this, you can use FIND_IN_SET(). Let us first create a table −mysql> create table DemoTable -> ( -> Number int -> ); Query OK, 0 rows affected (2.25 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.91 sec) mysql> insert into DemoTable values(60); Query OK, 1 row affected (0.69 sec) mysql> insert into DemoTable values(40); Query OK, 1 row affected (0.72 sec) mysql> insert into DemoTable values(800); Query OK, 1 row affected (0.75 sec)Display all records ... Read More
You can exclude a specific record in SQL using not equal to operator(!=). Let us first create a table−mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, ClientName varchar(20), ClientCountryName varchar(10) ); Query OK, 0 rows affected (0.64 sec)Insert records in the table using insert command −mysql> insert into DemoTable(ClientName, ClientCountryName) values('John', 'US'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(ClientName, ClientCountryName) values('David', 'AUS'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(ClientName, ClientCountryName) values('Mike', 'UK'); Query OK, 1 row affected (0.14 sec)Display all records from the ... Read More
This method retrieves the description of the columns of a table. It accepts 4 parameters −catalog - A string parameter representing the name (or, name pattern) of the catalog (database in general) in which the table (that contains the columns of which you need to retrieve the description about) exists. pass "" to get the description of the columns in tables with no catalog and, pass null if you don't want to use catalog and thus narrow the search.schemaPattern - A String parameter representing the name (or, name pattern) of the schema of the table, pass "" if in case ... Read More
You need to give name explicitly or you can remove AS command. Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(20) ); Query OK, 0 rows affected (0.21 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Name) values('John'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(Name) values('Larry'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(Name) values('Sam'); Query OK, 1 row affected (0.06 sec)Display all records from the table using select statement −mysql> select ... Read More
Create a JTextBox first −JTextField textField = new JTextField();Set the above JTextFile for the Default Cell Editor −TreeCellEditor editor = new DefaultCellEditor(textField); tree.setEditable(true); tree.setCellEditor(editor);The following is an example to create a default cell editor with textbox −Examplepackage my; import javax.swing.DefaultCellEditor; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.TreeCellEditor; public class SwingDemo { public static void main(String[] args) throws Exception { JFrame frame = new JFrame("Demo"); DefaultMutableTreeNode node = new DefaultMutableTreeNode("Products"); DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("Clothing"); DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("Electronics"); DefaultMutableTreeNode node3 ... Read More
Yes, for this, use $indexOfCP operator along with aggregate framework. Let us first create a collection with documents −> db.patterDemo.insertOne( { "ClientName": "John", "ClientWebsiteName":"webbuziness.com/John/business" } ); { "acknowledged" : true, "insertedId" : ObjectId("5cea40acef71edecf6a1f68d") } > db.patterDemo.insertOne( { "ClientName": "Carol", "ClientWebsiteName":"solvecoding.com/business" } ); { "acknowledged" : true, "insertedId" : ObjectId("5cea40acef71edecf6a1f68e") }Following is the query to display all documents from a collection with the help of find() method −> db.patterDemo.find().pretty();This will produce the following output −{ "_id" : ObjectId("5cea40acef71edecf6a1f68d"), "ClientName" : "John", "ClientWebsiteName" : "abcd.com" ... Read More
The area is a quantity that represents the extent of the figure in two dimensions. The area of a circle is the area covered by the circle in a two dimensional plane.To find the area of a circle, the radius[r] or diameter[d](2* radius) is required.The formula used to calculate the area is (π*r2) or {(π*d2)/4}.Example CodeTo find the area of a circle using radius. Live Demo#include int main(void) { float pie = 3.14; int radius = 6; printf("The radius of the circle is %d " , radius); float area = (float)(pie* radius * radius); printf("The ... Read More
To get the total number of rows in a MySQL database, you can use aggregate function SUM() along with inbuilt column TABLE_ROWS from INFORMATION_SCHEMA.TABLES.The syntax is as follows−SELECT SUM(TABLE_ROWS) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = database();Let’s say we are using the database with the name ‘sample’.Now we will get the total number of rows in a MySQL database−mysql> SELECT SUM(TABLE_ROWS) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = database();This will produce the following output−+-----------------+ | SUM(TABLE_ROWS) | +-----------------+ | 2043 | +-----------------+ 1 row in set (22.11 sec)