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：
<insert id="insert" parameterType="Post" useGeneratedKeys="true" keyProperty="id">
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