## 基礎例子 ```java /** * 入門 演示內置SQLManager用法和BaseMapper用法，項目中更推薦使用BaseMapper，而不是較為底層的SQLManager * @author xiandafu * */ public class S1QuickStart { SQLManager sqlManager; UserMapper mapper = null; public S1QuickStart(SQLManager sqlManager) { this.sqlManager = sqlManager; mapper = sqlManager.getMapper(UserMapper.class); } public static void main(String[] args) throws Exception { SQLManager sqlManager = SampleHelper.getSqlManager(); S1QuickStart quickStart = new S1QuickStart(sqlManager); quickStart.baseSqlManager(); quickStart.executeSql(); quickStart.executeTemplate(); quickStart.query(); quickStart.mapper(); quickStart.sqlResource(); } /** * 使用內置sqlManager方法 */ public void baseSqlManager(){ UserEntity user = sqlManager.unique(UserEntity.class,1); user.setName("ok123"); sqlManager.updateById(user); UserEntity newUser = new UserEntity(); newUser.setName("newUser"); newUser.setDepartmentId(1); sqlManager.insert(newUser); UserEntity template = new UserEntity(); template.setDepartmentId(1); List<UserEntity> list = sqlManager.template(template); } //執行sql語句方法 public void executeSql(){ String sql = "select * from user where id=?"; Integer id = 1; SQLReady sqlReady = new SQLReady(sql,new Object[id]); List<UserEntity> userEntities = sqlManager.execute(sqlReady,UserEntity.class); String updateSql = "update department set name=? where id =?"; String name="lijz"; SQLReady updateSqlReady = new SQLReady(updateSql,new Object[]{name,id}); sqlManager.executeUpdate(updateSqlReady); } //執行sql模板語句 public void executeTemplate(){ { String sql = "select * from user where department_id=#{id} and name=#{name}"; UserEntity paras = new UserEntity(); paras.setDepartmentId(1); paras.setName("lijz"); List<UserEntity> list = sqlManager.execute(sql,UserEntity.class,paras); } { //或者使用Map作為參數 String sql = "select * from user where department_id=#{myDeptId} and name=#{myName}"; Map paras = new HashMap(); paras.put("myDeptId",1); paras.put("myName","lijz"); List<UserEntity> list = sqlManager.execute(sql,UserEntity.class,paras); } { //使用Beetl模板語句 String sql = "select * from user where 1=1 \n" + "-- @if(isNotEmpty(myDeptId)){\n" + " and department_id=#{myDeptId}\t\n" + "-- @}\n" + "and name=#{myName}"; Map paras = new HashMap(); paras.put("myDeptId",1); paras.put("myName","lijz"); List<UserEntity> list = sqlManager.execute(sql,UserEntity.class,paras); } } public void query(){ { Query<UserEntity> query = sqlManager.query(UserEntity.class); List<UserEntity> entities = query.andEq("department_id",1) .andIsNotNull("name").select(); } { //使用LambdaQuery，能很好的支持數據庫重構 LambdaQuery<UserEntity> query = sqlManager.lambdaQuery(UserEntity.class); List<UserEntity> entities = query.andEq(UserEntity::getDepartmentId,1) .andIsNotNull(UserEntity::getName).select(); } } /** * 最常用的方式，編寫一個Mapper類，mapper方法提供數據庫訪問接口，beetlsql提供豐富的beetlsql實現 */ public void mapper(){ // 內置BaseMapper方法調用 List<UserEntity> list = mapper.all(); boolean isExist = mapper.exist(2); UserEntity me = mapper.unique(1); me.setName("newName"); mapper.updateById(me); //調用其他方法 UserEntity user = mapper.getUserById(1); UserEntity user2 = mapper.queryUserById(2); mapper.updateName("newName2",2); List<UserEntity> users = mapper.queryByNameOrderById("newName2"); List<DepartmentEntity> depts = mapper.findAllDepartment(); } /** * 對于復雜sql語句，比如幾十行，甚至幾百行的sql模板語句，放到markdown文件里是個不錯的想法 * 參考sql/user.md#select */ public void sqlResource(){ SqlId id = SqlId.of("user","select"); //or SqlId id = SqlId.of("user.select"); Map map = new HashMap(); map.put("name","n"); List<UserEntity> list = sqlManager.select(id,UserEntity.class,map); UserMapper mapper = sqlManager.getMapper(UserMapper.class); mapper.select("n"); } } ```