Jdbc connection example for implementing Mysql in Java _ MySQL

Java implementation of Mysql jdbc connection example bitsCN.com

First, create a database in the MySQL console
SQL code

Create database test;
Use test;
Create table user (username varchar (15), password varchar (20 ));
Insert into user values ('userone', '201312 ');
You can also use MySQL-Front to create

Java code

Package com. dgy. util;
Import java. SQL. Connection;
Import java. SQL. DriverManager;
Import java. SQL. ResultSet;
Import java. SQL. SQLException;
Import java. SQL. Statement;
Public class TestJDBC {
/**
* 1. the mysql driver package used is a mysql-connector-java-5.0.8-bin.jar
* 2. The Statement is used to execute a static SQL Statement and return the object of the result it generates.
* By default, only one ResultSet object can be opened for each Statement object at a time.
* Therefore, if you read a ResultSet object and read another object,
* The two objects must be generated by different Statement objects.
* If the current ResultSet object opened by a statement exists,
* All execution methods in the Statement interface are implicitly disabled.
* 3. ResultSet indicates the data table of the database result set, which is usually generated by executing a database query statement.
* The ResultSet object has a pointer to its current data row. Initially, the pointer is placed before the first line.
* The next method moves the pointer to the next row;
* Because this method returns false if there is no next row in the ResultSet object,
* You can use it in the while loop to iterate the result set.
**/
Static Connection conn = null;
Public static Connection getConnectionByJDBC (){
Try {
// Load the driver package
Class. forName (com. mysql. jdbc. Driver "); // load the Driver
} Catch (ClassNotFoundException e ){
System. out. println ("An exception occurred when loading the driver package! Please check it! ");
E. printStackTrace ();
}
Try {
/** Create a jdbc connection, but pay attention to the first parameter of this method,
* If a CommunicationsException exception occurs in 127.0.0.1,
* It may need to be changed to localhost.
**/
// Jdbc: mysql: // localhost: 3306/test, and test is a database
Conn = DriverManager. getConnection ("jdbc: mysql: // localhost: 3306/test", "root", "123456 ");
} Catch (SQLException e ){
System. out. println ("An exception occurred when connecting to the database! ");
E. printStackTrace ();
}
Return conn;
}
Public static void test (){
String SQL = "select * from user ";
GetConnectionByJDBC ();
Try {
// Create a jdbc statement
Statement stmt = conn. createStatement ();
// Execute the query
ResultSet rs = stmt.exe cuteQuery (SQL );
While (rs. next ()){
String username = rs. getString ("username ");
String password = rs. getString ("password ");
System. out. println (username + "" + password );
}
} Catch (SQLException e ){
System. out. println (e. getMessage ());
E. printStackTrace ();
} Finally {
// Closes the connection proactively (to avoid the connection being closed in the try statement block when an exception occurs)
Try {
If (conn! = Null) conn. close ();
} Catch (SQLException e ){
System. out. println (e. getMessage ());
E. printStackTrace ();
}
}
}
Public static void main (String [] args ){
TestJDBC testjdbc = new TestJDBC ();
Testjdbc. test ();
}
}

Author: "netsky"

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