[improvement][headless]Simplify query sql and fix demo.

headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/SqlQueryParser.java

@@ -65,7 +65,7 @@ public class SqlQueryParser implements QueryParser {
         // check if there are fields not matched with any metric or dimension
         if (allFields.size() > metricSchemas.size() + dimensions.size()) {
             queryStatement
-                    .setErrMsg("There are fields in the SQL not matched with any semantic column.");
+                    .setErrMsg("There are querying columns in the SQL not matched with any semantic field.");
             queryStatement.setStatus(1);
             return;
         }

headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/node/DimensionNode.java

@@ -14,7 +14,10 @@ public class DimensionNode extends SemanticNode {
     public static SqlNode build(Dimension dimension, SqlValidatorScope scope, EngineType engineType)
             throws Exception {
         SqlNode sqlNode = parse(dimension.getExpr(), scope, engineType);
-        return buildAs(dimension.getName(), sqlNode);
+        if (!dimension.getName().equals(dimension.getExpr())) {
+            sqlNode = buildAs(dimension.getName(), sqlNode);
+        }
+        return sqlNode;
     }
 
     public static List<SqlNode> expand(Dimension dimension, SqlValidatorScope scope,

headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/node/MeasureNode.java

@@ -9,7 +9,11 @@ public class MeasureNode extends SemanticNode {
 
     public static SqlNode buildNonAgg(String alias, Measure measure, SqlValidatorScope scope,
             EngineType engineType) throws Exception {
-        return buildAs(measure.getName(), getExpr(measure, alias, scope, engineType));
+        if (measure.getExpr() == null) {
+            return getExpr(measure, alias, scope, engineType);
+        } else {
+            return buildAs(measure.getName(), getExpr(measure, alias, scope, engineType));
+        }
     }
 
     public static SqlNode buildAgg(Measure measure, boolean noAgg, SqlValidatorScope scope,

headless/core/src/main/java/com/tencent/supersonic/headless/core/utils/SqlGenerateUtils.java

@@ -317,12 +317,12 @@ public class SqlGenerateUtils {
 
     public String getExpr(Measure measure, AggOption aggOption) {
         if (AggOperatorEnum.COUNT_DISTINCT.getOperator().equalsIgnoreCase(measure.getAgg())) {
-            return AggOption.NATIVE.equals(aggOption) ? measure.getBizName()
+            return AggOption.NATIVE.equals(aggOption) ? measure.getExpr()
                     : AggOperatorEnum.COUNT.getOperator() + " ( " + AggOperatorEnum.DISTINCT + " "
-                            + measure.getBizName() + " ) ";
+                            + measure.getExpr() + " ) ";
         }
-        return AggOption.NATIVE.equals(aggOption) ? measure.getBizName()
-                : measure.getAgg() + " ( " + measure.getBizName() + " ) ";
+        return AggOption.NATIVE.equals(aggOption) ? measure.getExpr()
+                : measure.getAgg() + " ( " + measure.getExpr() + " ) ";
     }
 
     public String getExpr(MetricResp metricResp) {