add throw exception sentences in some cases

Author: Liu Zhengyun

integration-test/src/test/java/org/apache/iotdb/ainode/it/AINodeForecastIT.java

@@ -44,7 +44,7 @@
 public class AINodeForecastIT {
 
   private static final String FORECAST_TABLE_FUNCTION_SQL_TEMPLATE =
-      "SELECT * FROM FORECAST(model_id=>'%s', input=>(SELECT time, s%d FROM db.AI) ORDER BY time)";
+      "SELECT * FROM FORECAST(model_id=>'%s', targets=>(SELECT time, s%d FROM db.AI) ORDER BY time)";
 
   @BeforeClass
   public static void setUp() throws Exception {
@@ -81,7 +81,7 @@ public void forecastTableFunctionTest() throws SQLException {
 
   public void forecastTableFunctionTest(
       Statement statement, AINodeTestUtils.FakeModelInfo modelInfo) throws SQLException {
-    // Invoke call inference for specified models, there should exist result.
+    // Invoke forecast table function for specified models, there should exist result.
     for (int i = 0; i < 4; i++) {
       String forecastTableFunctionSQL =
           String.format(FORECAST_TABLE_FUNCTION_SQL_TEMPLATE, modelInfo.getModelId(), i);
@@ -90,7 +90,7 @@ public void forecastTableFunctionTest(
         while (resultSet.next()) {
           count++;
         }
-        // Ensure the call inference return results
+        // Ensure the forecast sentence return results
         Assert.assertTrue(count > 0);
       }
     }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/function/tvf/ClassifyTableFunction.java

@@ -344,6 +344,7 @@ public void finish(
 
     private TsBlock classify() {
       int outputLength = inputRecords.size();
+      // construct inputTSBlock for AINode
       while (!inputRecords.isEmpty()) {
         Record row = inputRecords.removeFirst();
         inputTsBlockBuilder.getTimeColumnBuilder().writeLong(row.getLong(0));

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/function/tvf/ForecastTableFunction.java

@@ -292,7 +292,7 @@ public TableFunctionAnalysis analyze(Map<String, Argument> arguments) {
 
     List<Type> targetColumnTypes = new ArrayList<>();
     List<Optional<String>> allInputColumnsName = targets.getFieldNames();
-    List<Type> allTargetColumnsType = targets.getFieldTypes();
+    List<Type> allInputColumnsType = targets.getFieldTypes();
 
     // predicated columns = all input columns except timecol / partition by columns
     for (int i = 0, size = allInputColumnsName.size(); i < size; i++) {
@@ -302,13 +302,20 @@ public TableFunctionAnalysis analyze(Map<String, Argument> arguments) {
         continue;
       }
 
-      Type columnType = allTargetColumnsType.get(i);
+      Type columnType = allInputColumnsType.get(i);
       targetColumnTypes.add(columnType);
       checkType(columnType, fieldName.get());
       requiredIndexList.add(i);
       properColumnSchemaBuilder.addField(fieldName.get(), columnType);
     }
 
+    if (targetColumnTypes.size() > 1) {
+      throw new SemanticException(
+          String.format(
+              "%s should not contain more than one target column, found [%s] target columns.",
+              TARGETS_PARAMETER_NAME, targetColumnTypes.size()));
+    }
+
     boolean keepInput =
         (boolean) ((ScalarArgument) arguments.get(KEEP_INPUT_PARAMETER_NAME)).getValue();
     if (keepInput) {
@@ -478,6 +485,12 @@ public void finish(
       }
       long outputTime =
           (outputStartTime == Long.MIN_VALUE) ? (inputEndTime + interval) : outputStartTime;
+      if (outputTime <= inputEndTime) {
+        throw new SemanticException(
+            String.format(
+                "The %s should be greater than the maximum timestamp of target time series. Expected greater than [%s] but found [%s].",
+                OUTPUT_START_TIME, inputEndTime, outputTime));
+      }
       for (int i = 0; i < outputLength; i++) {
         properColumnBuilders.get(0).writeLong(outputTime + interval * i);
       }
@@ -517,6 +530,7 @@ public void finish(
     }
 
     private TsBlock forecast() {
+      // construct inputTSBlock for AINode
       while (!inputRecords.isEmpty()) {
         Record row = inputRecords.removeFirst();
         inputTsBlockBuilder.getTimeColumnBuilder().writeLong(row.getLong(0));