好久沒(méi)有編寫有關(guān)數(shù)據(jù)庫(kù)應(yīng)用程序啦,這里回顧一下java JDBC。
1.使用Java JDBC操作數(shù)據(jù)庫(kù)一般需要6步:
(1)建立JDBC橋接器,加載數(shù)據(jù)庫(kù)驅(qū)動(dòng);
(2)連接數(shù)據(jù)庫(kù),獲得Connection對(duì)象(使用數(shù)據(jù)庫(kù)連接地址,用戶名,密碼);
(3)獲得數(shù)據(jù)庫(kù)Statement對(duì)象;
(4)執(zhí)行數(shù)據(jù)庫(kù)操作;
(5)讀取結(jié)果;
(6)關(guān)閉數(shù)據(jù)庫(kù)連接;
2.使用Java JDBC操作數(shù)據(jù)庫(kù)(mysql)代碼:
連接mysql數(shù)據(jù)庫(kù),需要導(dǎo)入mysql數(shù)據(jù)庫(kù)jar包,本代碼使用mysql-connector-java-5.1.18-bin.jar。
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import java.sql.Connection; import java.sql.DriverManager; import java.sql.Statement; import java.sql.ResultSet; public class MyTest { public static void main(String args[]) { Connection con = null ; Statement st = null ; ResultSet rs = null ; try { // 獲得MySQL驅(qū)動(dòng)的實(shí)例 Class.forName( "com.mysql.jdbc.Driver" ).newInstance(); // 獲得連接對(duì)象(提供:地址,用戶名,密碼) con = DriverManager.getConnection( "jdbc:mysql://127.0.0.1/Weather" , "root" , "root" ); if (!con.isClosed()) System.out.println( "Successfully connected " ); else System.out.println( "failed connected" ); //建立一個(gè)Statement,數(shù)據(jù)庫(kù)對(duì)象 st = con.createStatement(); // 運(yùn)行SQL查詢語(yǔ)句 rs = st.executeQuery( "select * from Weather.question_type_1;" ); // 讀取結(jié)果集 while (rs.next()) { System.out.println( "column1:" +rs.getInt( 1 )); System.out.println( "column2:" +rs.getString( 2 )); System.out.println( "column3:" +rs.getString( 3 )); System.out.println( "column4:" +rs.getString( 4 )); } // 關(guān)閉鏈接 con.close(); } catch (Exception e) { System.err.println( "Exception: " + e.getMessage()); } } } |