Count Rows from a Database Table
After creating a database table, if we want to know
number of rows in a table then we can get it very easily by using the simple
database query. See brief description
below:
Description of program:
For this program to work firstly we need to establish
the connection
with MySQL database by the help of JDBC driver. When the connection has been
established we need to pass a table name from the given database in the query
and the rows will be counted and the result will be displayed. If any exception is thrown then
it will show "SQL statement is
not executed!"
Description of code:
SELECT COUNT(*) FROM
table_name;
This code is used to count the rows of given
table.
table_name: It is a name of
the table of which we want to see the rows.
Here is the code of program:
import java.io.*;
import java.sql.*;
public class CountRows{
public static void main(String[] args) {
System.out.println("Count number of rows in a specific table!");
Connection con = null;
int count = 0;
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection
("jdbc:mysql://localhost:3306/jdbctutorial","root","root");
try{
Statement st = con.createStatement();
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter table name:");
String table = bf.readLine();
ResultSet res = st.executeQuery("SELECT COUNT(*) FROM "+table);
while (res.next()){
count = res.getInt(1);
}
System.out.println("Number of column:"+count);
}
catch (SQLException s){
System.out.println("SQL statement is not executed!");
}
}
catch (Exception e){
e.printStackTrace();
}
}
}
|
Download this example.
output of program:
C:\vinod\jdbc\jdbc\jdbc-mysql>javac CountRows.java
C:\vinod\jdbc\jdbc\jdbc-mysql>java CountRows
Count number of rows in a specific table!
Enter table name:
student
Number of column:6 |
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