代码如下: EnvironmentSettings bbSettings = EnvironmentSettings.newInstance().useBlinkPlanner().inBatchMode().build(); TableEnvironment tableEnv = TableEnvironment.create(bbSettings); tableEnv.executeSql("CREATE TABLE t_yyp_test (\n" + " f_id INT,\n" + " f_h STRING,\n" + " f_l STRING,\n" + " f_j STRING,\n" + " f_value DOUBLE,\n" + " f_time TIMESTAMP(3)\n, " + " f_time_bak TIMESTAMP(3)\n, " + " PRIMARY KEY (f_id) NOT ENFORCED,\n" + " WATERMARK FOR f_time AS f_time \n" + ") WITH (\n" + " 'connector' = 'jdbc',\n" + " 'url' = 'jdbc:mysql://***',\n" + " 'table-name' = '123',\n" + " 'username' = '123',\n" + " 'password' = '123'\n" + ")"); tableEnv.registerFunction("GaussianFunction", new GaussianFunction()); Table table = tableEnv .from("t_yyp_test") .window(Over.partitionBy($("f_h"), $("f_l"), $("f_j")) .orderBy($("f_time_bak")) .preceding("unbounded_range") .following(CURRENT_RANGE) .as("w")) .select($("f_h"), $("f_l"), $("f_j"), $("f_value").avg().over($("w")), $("f_value").varPop().over($("w")), $("f_value").stddevPop().over($("w")));
已经定义了eventTime 使用eventTIme或者别的时间字段排序都报错 Exception in thread "main" org.apache.flink.table.api.ValidationException: Ordering must be defined on a time attribute. 请问这是什么原因