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Articles by Anvi Jain
Page 26 of 43
Java DatabaseMetaData getMaxColumnsInSelect() method with example.
The getMaxColumnsInSelect() method of the DatabaseMetaData interface is used to find out the maximum number of columns that the underlying database allows in a SELECT list.This method returns an integer value, representing the maximum number of columns allowed in a SELECT list. If this value is 0 it indicates that there is no limit or, limit is unknown.To get the DatabaseMetaData object −Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of ...
Read MoreCounting presence of a NOT NULL value in MySQL
To count presence of a NOT NULL value, use aggregate function COUNT(yourColumnName). Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, NumberOfQuestion int, NumberOfSolution int ); Query OK, 0 rows affected (0.20 sec)Insert some records in the table using insert command. Here, some of the values are NULL −mysql> insert into DemoTable(NumberOfQuestion, NumberOfSolution) values(20, 10); Query OK, 1 row affected (0.06 sec) mysql> insert into DemoTable(NumberOfQuestion, NumberOfSolution) values(20, 2); Query OK, 1 row affected (0.04 sec) mysql> insert into DemoTable(NumberOfQuestion, NumberOfSolution) values(20, NULL); Query ...
Read MoreJava DatabaseMetaData getMaxRowSize() method with example.
The getMaxRowSize() method of the DatabaseMetaData interface is used to find out the maximum number of bytes that the underlying database allows in a row.This method returns an integer value, representing the maximum row size. If this value is 0 it indicates that there is no limit or, limit is unknown.To get the DatabaseMetaData object −Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of the DriverManager class. Pass the URL the ...
Read MoreHow can I find all columns where the column name length is greater than 5 in MySQL?
Use HAVING to find all columns where the column name length is greater than 5. This will produce the following output −+-------------------+-------------------------+ | TABLE_NAME | COLUMN_NAME | +-------------------+-------------------------+ | DemoTable | UserId | | DemoTable | EndDate | | DemoTable | StartDate | | DemoTable | StudentFavouriteSubject | | DemoTable ...
Read MoreHow can I calculate the total value of products from my MySQL product table?
Let us first create a table −mysql> create table DemoTable ( ProductId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ProductQuantity int, ProductPrice int ); Query OK, 0 rows affected (0.19 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(ProductQuantity, ProductPrice) values(10, 100); Query OK, 1 row affected (0.06 sec) mysql> insert into DemoTable(ProductQuantity, ProductPrice) values(5, 11); Query OK, 1 row affected (0.04 sec) mysql> insert into DemoTable(ProductQuantity, ProductPrice) values(3, 140); Query OK, 1 row affected (0.05 sec) mysql> insert into DemoTable(ProductQuantity, ProductPrice) values(2, 450); Query OK, 1 row affected ...
Read MoreJava DatabaseMetaData getMaxTablesInSelect() method with example.
The getMaxTablesInSelect() method of the DatabaseMetaData interface is used to find out the maximum number of tables that the underlying database allows in an SQL SELECT statement.This method returns an integer value, representing the maximum number of tables allowed in a SELECT statement. If this value is 0 it indicates that there is no limit or, limit is unknown.To get the DatabaseMetaData object −Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method ...
Read MoreMySQL filtering by multiple columns?
To perform filtering by multiple columns, use where clause along with OR. Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(10), Score int ); Query OK, 0 rows affected (0.28 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Name, Score) values('John', 80); Query OK, 1 row affected (0.04 sec) mysql> insert into DemoTable(Name, Score) values('John', 90); Query OK, 1 row affected (0.06 sec) mysql> insert into DemoTable(Name, Score) values('Carol', 89); Query OK, 1 row affected (0.04 sec) ...
Read MoreHow can I order in group but randomly with MySQL?
Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value char(1) ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Value) values('X'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Value) values('Y'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable(Value) values('X'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable(Value) values('X'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(Value) values('Y'); Query OK, 1 ...
Read MoreHow to set all the Arrow Buttons in a frame with Java?
To set arrow buttons in a frame, let us first create a frame −JFrame frame = new JFrame();Now, set the layout for the frame wherein all the arrow buttons would be displayed −frame.setLayout(new GridLayout(0, 5));Set the arrow buttons for all the locations −frame.add(new BasicArrowButton(BasicArrowButton.EAST)); frame.add(new BasicArrowButton(BasicArrowButton.NORTH)); frame.add(new BasicArrowButton(BasicArrowButton.SOUTH)); frame.add(new BasicArrowButton(BasicArrowButton.WEST));The following is an example to set all the arrow buttons in a frame −Examplepackage my; import java.awt.GridLayout; import javax.swing.Box; import javax.swing.Icon; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.plaf.basic.BasicArrowButton; public class SwingDemo { public static void main(String[] args) { JButton button1 = new JButton("One"); ...
Read MoreNew line separator doesn't work for group_concat function in MySQL? How to use it correctly?
To use new line separator in group_concat() function, follow the below syntax −select group_concat(concat_ws(' ', yourColumnName1, yourColumnName2) SEPARATOR "\r") from yourTableName;Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(20), LastName varchar(20) ); Query OK, 0 rows affected (0.67 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(FirstName, LastName) values('John', 'Smith'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(FirstName, LastName) values('David', 'Miller'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FirstName, LastName) values('John', 'Doe'); ...
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