SQLDatabase drop the column names in the result. (#15361)

Fix for the following bug:
https://github.com/langchain-ai/langchain/issues/15360

---------

Co-authored-by: dudu butbul <100126964+dudu-upstream@users.noreply.github.com>

libs/community/langchain_community/utilities/sql_database.py

@@ -427,6 +427,7 @@ class SQLDatabase:
         self,
         command: str,
         fetch: Union[Literal["all"], Literal["one"]] = "all",
+        include_columns: bool = False,
     ) -> str:
         """Execute a SQL command and return a string representing the results.
 
@@ -434,12 +435,18 @@ class SQLDatabase:
         If the statement returns no rows, an empty string is returned.
         """
         result = self._execute(command, fetch)
-        # Convert columns values to string to avoid issues with sqlalchemy
-        # truncating text
+
         res = [
-            tuple(truncate_word(c, length=self._max_string_length) for c in r.values())
+            {
+                column: truncate_word(value, length=self._max_string_length)
+                for column, value in r.items()
+            }
             for r in result
         ]
+
+        if not include_columns:
+            res = [tuple(row.values()) for row in res]
+
         if not res:
             return ""
         else:
@@ -465,6 +472,7 @@ class SQLDatabase:
         self,
         command: str,
         fetch: Union[Literal["all"], Literal["one"]] = "all",
+        include_columns: bool = False,
     ) -> str:
         """Execute a SQL command and return a string representing the results.
 
@@ -474,7 +482,7 @@ class SQLDatabase:
         If the statement throws an error, the error message is returned.
         """
         try:
-            return self.run(command, fetch)
+            return self.run(command, fetch, include_columns)
         except SQLAlchemyError as e:
             """Format the error message"""
             return f"Error: {e}"

libs/langchain/tests/unit_tests/test_sql_database.py

@@ -120,10 +120,16 @@ def test_sql_database_run() -> None:
         conn.execute(stmt)
     db = SQLDatabase(engine)
     command = "select user_id, user_name, user_bio from user where user_id = 13"
-    output = db.run(command)
+    partial_output = db.run(command)
     user_bio = "That is my Bio " * 19 + "That is my..."
-    expected_output = f"[(13, 'Harrison', '{user_bio}')]"
-    assert output == expected_output
+    expected_partial_output = f"[(13, 'Harrison', '{user_bio}')]"
+    assert partial_output == expected_partial_output
+
+    full_output = db.run(command, include_columns=True)
+    expected_full_output = (
+        "[{'user_id': 13, 'user_name': 'Harrison', 'user_bio': '%s'}]" % user_bio
+    )
+    assert full_output == expected_full_output
 
 
 def test_sql_database_run_update() -> None: