to fix table without alias

Author: fupelaqu

es6/sql-bridge/src/test/scala/app/softnetwork/elastic/sql/SQLQuerySpec.scala

@@ -3436,7 +3436,7 @@ class SQLQuerySpec extends AnyFlatSpec with Matchers {
         |    "aggs": {
         |        "avg_popularity": {
         |            "avg": {
-        |                "field": "blogs.popularity"
+        |                "field": "popularity"
         |            }
         |        },
         |        "nested_comments": {

sql/bridge/src/test/scala/app/softnetwork/elastic/sql/SQLQuerySpec.scala

@@ -3436,7 +3436,7 @@ class SQLQuerySpec extends AnyFlatSpec with Matchers {
         |    "aggs": {
         |        "avg_popularity": {
         |            "avg": {
-        |                "field": "blogs.popularity"
+        |                "field": "popularity"
         |            }
         |        },
         |        "nested_comments": {

sql/src/main/scala/app/softnetwork/elastic/sql/query/From.scala

@@ -148,7 +148,12 @@ case class From(tables: Seq[Table]) extends Updateable {
     .flatten
 
   lazy val tableAliases: Map[String, String] = tables
-    .flatMap((table: Table) => table.tableAlias.map(alias => table.name -> alias.alias))
+    .flatMap((table: Table) =>
+      table.tableAlias match {
+        case Some(alias) if alias.alias.nonEmpty => Some(table.name -> alias.alias)
+        case _                                   => Some(table.name -> table.name)
+      }
+    )
     .toMap ++ unnestAliases.map(unnest => unnest._2._1 -> unnest._1)
 
   lazy val unnestAliases: Map[String, (String, Option[Limit])] = unnests