Which command is used to short rows in SQL?
Which one of the following options given matches with the shorts row in SQL? Here are the options given below:-
1. DISTINCT
2. LIMIT
3. GROUP BY
4. ORDER BY
In the context of SQL, the option that is correct among all the options is option 2 which refers to the LIMIT. The LIMIT Clause is used in SQL queries to restrict the number of rows returned by a particular query. It is usually useful when you want to retrieve only a specific number of rows from the set of results. The syntax for the LIMIT varies slightly different different SQL dialects. Here is the basic example given of LIMIT by using MySQL and JDBC:-
Import java.sql.*;
Public class Example {
Public static void main(String[] args) {
String url = “jdbc:mysql://localhost:3306/your_database_name”;
String username = “your_username”;
String password = “your_password”;
Try (Connection conn = DriverManager.getConnection(url, username, password)) {
String sql = “SELECT * FROM your_table_name LIMIT 10”; // Example query with LIMIT
Try (Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql)) {
While (rs.next()) {
// Retrieve data from the result set
Int id = rs.getInt(“id”);
String name = rs.getString(“name”);
// Process the retrieved data
System.out.println(“ID: “ + id + “, Name: “ + name);
}
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
In the context of SQL, the DISTINCT keyword is mainly used in retrieving the unique values across the specified columns in a query result set. It would help you filter out the duplicate rows based on the specific columns which would ensure that each row in the results should be unique. Here is the example given of it:-
Import java.sql.*;
Public class Example {
Public static void main(String[] args) {
String url = “jdbc:mysql://localhost:3306/your_database_name”;
String username = “your_username”;
String password = “your_password”;
Try (Connection conn = DriverManager.getConnection(url, username, password)) {
String sql = “SELECT DISTINCT age FROM students”;
Try (Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql)) {
While (rs.next()) {
// Retrieve data from the result set
Int age = rs.getInt(“age”);
// Process the retrieved data
System.out.println(“Age: “ + age);
}
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
The GROUP BY refers to the Clause which can be used for grouping the rows with the same value. It is generally used in conjunction with aggregate functions such as COUNT, SUM, AVG, etc to perform operations on each group of the rows. Here is the example given of it:-
Import java.sql.*;
Public class Example {
Public static void main(String[] args) {
String url = “jdbc:mysql://localhost:3306/your_database_name”;
String username = “your_username”;
String password = “your_password”;
Try (Connection conn = DriverManager.getConnection(url, username, password)) {
String sql = “SELECT customer_id, SUM(total_amount) AS total_sales FROM orders GROUP BY customer_id”;
Try (Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql)) {
While (rs.next()) {
// Retrieve data from the result set
Int customerId = rs.getInt(“customer_id”);
Double totalSales = rs.getDouble(“total_sales”);
// Process the retrieved data
System.out.println(“Customer ID: “ + customerId + “, Total Sales: “ + totalSales);
}
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
The ORDER BY Clause is mainly used in sorting the results set of a particular query by one or more columns in ascending or descending order. It can allow you to control the order in which rows are returned in the query results. Here is the example given of it:-
Import java.sql.*;
Public class Example {
Public static void main(String[] args) {
String url = “jdbc:mysql://localhost:3306/your_database_name”;
String username = “your_username”;
String password = “your_password”;
Try (Connection conn = DriverManager.getConnection(url, username, password)) {
String sql = “SELECT product_id, product_name, price, stock_quantity FROM products ORDER BY price DESC”;
Try (Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql)) {
While (rs.next()) {
// Retrieve data from the result set
Int productId = rs.getInt(“product_id”);
String productName = rs.getString(“product_name”);
Double price = rs.getDouble(“price”);
Int stockQuantity = rs.getInt(“stock_quantity”);
// Process the retrieved data
System.out.println(“Product ID: “ + productId + “, Name: “ + productName + “, Price: “ + price + “, Stock Quantity: “ + stockQuantity);
}
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}