使用java查询MySQL数据库

伙计们，简单地说，我有一个带有文本输出框的java应用程序。 我想查询Db并将输出显示到文本框中。

实施例I具有带有两列food和color的Db

我想 ：

 SELECT * in Table WHERE color = 'blue' 

有什么建议么？

Answer 1

初学者通常在理解如何从Java连接MySQL时遇到问题。 这是可以帮助您快速启动和运行的代码段。 你必须从某个地方获取mysql jdbc驱动程序jar文件（google it）并将其添加到类路径中。

 Class.forName("com.mysql.jdbc.Driver") ; Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/DBNAME", "usrname", "pswd") ; Statement stmt = conn.createStatement() ; String query = "select columnname from tablename ;" ; ResultSet rs = stmt.executeQuery(query) ; 

Answer 2

你应该使用JDBC。 请参见http://en.wikipedia.org/wiki/Java_Database_Connectivity

您需要http://dev.mysql.com/downloads/connector/j/上的Java MySQL Connector

然后使用类似的东西（从维基百科文章中复制）：

 Class.forName( "com.mysql.jdbc.driver" ); Connection conn = DriverManager.getConnection( "jdbc:mysql://localhost/database", "myLogin", "myPassword" ); try { Statement stmt = conn.createStatement(); try { ResultSet rs = stmt.executeQuery( "SELECT * FROM Table WHERE color = 'blue'" ); try { while ( rs.next() ) { int numColumns = rs.getMetaData().getColumnCount(); for ( int i = 1 ; i <= numColumns ; i++ ) { // Column numbers start at 1. // Also there are many methods on the result set to return // the column as a particular type. Refer to the Sun documentation // for the list of valid conversions. System.out.println( "COLUMN " + i + " = " + rs.getObject(i) ); } } } finally { try { rs.close(); } catch (Throwable ignore) { /* Propagate the original exception instead of this one that you may want just logged */ } } } finally { try { stmt.close(); } catch (Throwable ignore) { /* Propagate the original exception instead of this one that you may want just logged */ } } } finally { //It's important to close the connection when you are done with it try { conn.close(); } catch (Throwable ignore) { /* Propagate the original exception instead of this one that you may want just logged */ } }