feat: support Elasticsearch datasource #108

Author: XiaJunjie2020

backend/apps/datasource/crud/datasource.py

@@ -293,6 +293,10 @@ def preview(session: SessionDep, current_user: CurrentUser, id: int, data: Table
         sql = f"""SELECT "{'", "'.join(fields)}" FROM "{conf.dbSchema}"."{data.table.table_name}" 
             {where} 
             LIMIT 100"""
+    elif ds.type == "es":
+        sql = f"""SELECT "{'", "'.join(fields)}" FROM "{data.table.table_name}" 
+            {where} 
+            LIMIT 100"""
     return exec_sql(ds, sql, True)