mysql获取自增长id

原生jdbc方式：

Statement.getGeneratedKeys()

示例：

Statement stmt = null;ResultSet rs = null;try { // // Create a Statement instance that we can use for // ‘normal‘ result sets assuming you have a // Connection ‘conn‘ to a MySQL database already // available stmt = conn.createStatement(); // // Issue the DDL queries for the table for this example // stmt.executeUpdate("ｄｒｏｐ TABLE IF EXISTS autoIncTutorial"); stmt.executeUpdate( "CREATE TABLE autoIncTutorial (" + "priKey INT NOT NULL AUTO_INCREMENT, " + "dataField VARCHAR(64), PRIMARY KEY (priKey))"); // // ｉｎｓｅｒｔ one row that will generate an AUTO INCREMENT // key in the ‘priKey‘ field // stmt.executeUpdate( "ｉｎｓｅｒｔ INTO autoIncTutorial (dataField) " + "values (‘Can I Get the Auto Increment Field?‘)", Statement.RETURN_GENERATED_KEYS); // // Example of using Statement.getGeneratedKeys() // to retrieve the value of an auto-increment // value // int autoIncKeyFromApi = -1; rs = stmt.getGeneratedKeys(); if (rs.next()) { autoIncKeyFromApi = rs.getInt(1); } else { // throw an exception from here } System.out.println("Key returned from getGeneratedKeys():" + autoIncKeyFromApi);} finally { if (rs != null) { try { rs.close(); } catch (SQLException ex) { // ignore } } if (stmt != null) { try { stmt.close(); } catch (SQLException ex) { // ignore } }}

也有使用ｓｅｌｅｃｔ LAST_INSERT_ID() 注意：并发可能会出现问题。示例：

Statement stmt = null;ResultSet rs = null;try { // // Create a Statement instance that we can use for // ‘normal‘ result sets. stmt = conn.createStatement(); // // Issue the DDL queries for the table for this example // stmt.executeUpdate("ｄｒｏｐ TABLE IF EXISTS autoIncTutorial"); stmt.executeUpdate( "CREATE TABLE autoIncTutorial (" + "priKey INT NOT NULL AUTO_INCREMENT, " + "dataField VARCHAR(64), PRIMARY KEY (priKey))"); // // ｉｎｓｅｒｔ one row that will generate an AUTO INCREMENT // key in the ‘priKey‘ field // stmt.executeUpdate( "ｉｎｓｅｒｔ INTO autoIncTutorial (dataField) " + "values (‘Can I Get the Auto Increment Field?‘)"); // // Use the MySQL LAST_INSERT_ID() // function to do the same thing as getGeneratedKeys() // int autoIncKeyFromFunc = -1; rs = stmt.executeQuery("ｓｅｌｅｃｔ LAST_INSERT_ID()"); if (rs.next()) { autoIncKeyFromFunc = rs.getInt(1); } else { // throw an exception from here } System.out.println("Key returned from " + "‘ｓｅｌｅｃｔ LAST_INSERT_ID()‘: " + autoIncKeyFromFunc);} finally { if (rs != null) { try { rs.close(); } catch (SQLException ex) { // ignore } } if (stmt != null) { try { stmt.close(); } catch (SQLException ex) { // ignore } }}

mybatis封装后的配置如下：

调用

postDao.add(post);和以前一样结果后返回1，使用post.getId()可以获取到自增的id。

参考文献：

【1】http://dev.mysql.com/doc/connector-j/en/connector-j-usagenotes-last-ｉｎｓｅｒｔ-id.html

【2】http://stackoverflow.com/questions/12241260/get-auto-genearated-key-for-the-inserted-record-in-mybatis