--raw option, refs #123

docs/cli.rst

@@ -142,6 +142,17 @@ You can use the ``--fmt`` (or ``-f``) option to specify different table formats,
 
 For a full list of table format options, run ``sqlite-utils query --help``.
 
+.. _cli_query_raw:
+
+Returning raw data from a query, such as binary content
+=======================================================
+
+If your table contains binary data in a ``BLOB`` you can use the ``--raw`` option to output specific columns directly to standard out.
+
+For example, to retrieve a binary image from a ``BLOB`` column and store it in a file you can use the following::
+
+    $ sqlite-utils photos.db "select contents from photos where id=1" --raw > myphoto.jpg
+
 .. _cli_rows:
 
 Returning all rows in a table

sqlite_utils/cli.py

@@ -675,7 +675,8 @@ def drop_view(path, view):
 )
 @click.argument("sql")
 @output_options
-def query(path, sql, nl, arrays, csv, no_headers, table, fmt, json_cols):
+@click.option("-r", "--raw", is_flag=True, help="Raw output, first column of first row")
+def query(path, sql, nl, arrays, csv, no_headers, table, fmt, json_cols, raw):
     "Execute SQL query and return the results as JSON"
     db = sqlite_utils.Database(path)
     with db.conn:
@@ -686,7 +687,13 @@ def query(path, sql, nl, arrays, csv, no_headers, table, fmt, json_cols):
             cursor = [[cursor.rowcount]]
         else:
             headers = [c[0] for c in cursor.description]
-        if table:
+        if raw:
+            data = cursor.fetchone()[0]
+            if isinstance(data, bytes):
+                sys.stdout.buffer.write(data)
+            else:
+                sys.stdout.write(str(data))
+        elif table:
             print(tabulate.tabulate(list(cursor), headers=headers, tablefmt=fmt))
         elif csv:
             writer = csv_std.writer(sys.stdout)

tests/test_cli.py

@@ -797,6 +797,21 @@ def test_query_json_with_json_cols(db_path):
     assert expected == result_rows.output.strip()
 
 
+@pytest.mark.parametrize(
+    "content,is_binary",
+    [(b"\x00\x0Fbinary", True), ("this is text", False), (1, False), (1.5, False)],
+)
+def test_query_raw(db_path, content, is_binary):
+    Database(db_path)["files"].insert({"content": content})
+    result = CliRunner().invoke(
+        cli.cli, [db_path, "select content from files", "--raw"]
+    )
+    if is_binary:
+        assert result.stdout_bytes == content
+    else:
+        assert result.output == str(content)
+
+
 def test_query_memory_does_not_create_file(tmpdir):
     owd = os.getcwd()
     try: