使用java查詢MySQL數據庫

Question

夥計們，簡單地說，我有一個帶有文本輸出框的java應用程序。我想查詢一個Db並將輸出顯示到文本框中。

比如我有一個兩列food和color

一個Db的，我想：

SELECT * in Table WHERE color = 'blue' 

有什麼建議？

Answer 1

初學者普遍面臨瞭解如何從Java連接到MySQL的問題。這是可以讓你快速啓動並運行的代碼片段。您必須從某處獲取mysql jdbc驅動程序jar文件（google它）並將其添加到類路徑中。

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

您應該使用JDBC。見http://en.wikipedia.org/wiki/Java_Database_Connectivity

您從http://dev.mysql.com/downloads/connector/j/

需要Java MySQL連接，然後使用類似（從維基百科的文章複製）：

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 */ } 
}