separate columns by tabs instead of single space in sql sample rows (langchain-ai#1348)

Use tabs to separate columns instead of a single space - confusing when there are spaces in a cell

Author: jzluo

docs/modules/chains/examples/sqlite.ipynb

@@ -379,9 +379,17 @@
  ")\n",
  "\n",
  "SELECT * FROM 'Track' LIMIT 2;\n",
- "TrackId Name AlbumId MediaTypeId GenreId Composer Milliseconds Bytes UnitPrice\n",
- "1 For Those About To Rock (We Salute You) 1 1 1 Angus Young, Malcolm Young, Brian Johnson 343719 11170334 0.99\n",
- "2 Balls to the Wall 2 2 1 None 342562 5510424 0.99\n"
+ "TrackId\tName\tAlbumId\tMediaTypeId\tGenreId\tComposer\tMilliseconds\tBytes\tUnitPrice\n",
+ "1\tFor Those About To Rock (We Salute You)\t1\t1\t1\tAngus Young, Malcolm Young, Brian Johnson\t343719\t11170334\t0.99\n",
+ "2\tBalls to the Wall\t2\t2\t1\tNone\t342562\t5510424\t0.99\n"
+ ]
+ },
+ {
+ "name": "stderr",
+ "output_type": "stream",
+ "text": [
+ "/home/jon/projects/langchain/langchain/sql_database.py:121: SAWarning: Dialect sqlite+pysqlite does *not* support Decimal objects natively, and SQLAlchemy must convert from floating point - rounding errors and other issues may occur. Please consider storing Decimal numbers as strings or integers on this platform for lossless storage.\n",
+ " sample_rows = connection.execute(command)\n"
  ]
  }
  ],

langchain/sql_database.py

@@ -133,7 +133,7 @@ def get_table_info(self, table_names: Optional[List[str]] = None) -> str:
  )
 
  # save the columns in string format
- columns_str = " ".join([col.name for col in table.columns])
+ columns_str = "\t".join([col.name for col in table.columns])
 
  try:
  # get the sample rows
@@ -145,7 +145,7 @@ def get_table_info(self, table_names: Optional[List[str]] = None) -> str:
  )
 
  # save the sample rows in string format
- sample_rows_str = "\n".join([" ".join(row) for row in sample_rows])
+ sample_rows_str = "\n".join(["\t".join(row) for row in sample_rows])
 
  # in some dialects when there are no rows in the table a
  # 'ProgrammingError' is returned