Add Browse data panel (table dropdown + row preview)

app.py

@@ -223,6 +223,47 @@ def schema_map_html(uploaded_db: str | None) -> str:
         return f"<p>Could not read database: {html.escape(str(exc))}</p>"
 
 
+def _list_tables(db_path: str) -> list[str]:
+    con = sqlite3.connect(f"file:{db_path}?mode=ro", uri=True)
+    tables = [
+        r[0] for r in con.execute(
+            "SELECT name FROM sqlite_master WHERE type='table' "
+            "AND name NOT LIKE 'sqlite_%' ORDER BY name"
+        )
+    ]
+    con.close()
+    return tables
+
+
+def browse_table(uploaded_db: str | None, table_name: str | None) -> pd.DataFrame:
+    """Return the first rows of the selected table (read-only preview)."""
+    if not table_name:
+        return pd.DataFrame()
+    db_path, err = resolve_db(uploaded_db)
+    if err:
+        return pd.DataFrame()
+    try:
+        con = sqlite3.connect(f"file:{db_path}?mode=ro", uri=True)
+        # table_name comes from our own dropdown (populated from sqlite_master).
+        cur = con.execute(f'SELECT * FROM "{table_name}" LIMIT 10')
+        cols = [d[0] for d in cur.description]
+        data = cur.fetchall()
+        con.close()
+        return pd.DataFrame(data, columns=cols)
+    except Exception:  # noqa: BLE001
+        return pd.DataFrame()
+
+
+def refresh_browser(uploaded_db: str | None):
+    """Repopulate the table dropdown and preview the first table's rows."""
+    db_path, err = resolve_db(uploaded_db)
+    if err:
+        return gr.update(choices=[], value=None), pd.DataFrame()
+    tables = _list_tables(db_path)
+    first = tables[0] if tables else None
+    return gr.update(choices=tables, value=first), browse_table(uploaded_db, first)
+
+
 def prefetch_weights() -> None:
     """Download weights to disk at startup (CPU, no GPU timer).
 
@@ -303,6 +344,10 @@ with gr.Blocks(title="LocalSQL") as demo:
     with gr.Accordion("What's in this database? (tables, columns, keys)", open=True):
         schema_map = gr.HTML()
 
+    with gr.Accordion("Browse data (peek at rows)", open=False):
+        table_dropdown = gr.Dropdown(label="Table", choices=[], interactive=True)
+        browse_df = gr.Dataframe(label="First 10 rows", interactive=False)
+
     with gr.Row():
         with gr.Column(scale=1):
             uploaded_db = gr.File(
@@ -346,10 +391,15 @@ with gr.Blocks(title="LocalSQL") as demo:
         inputs=[question, evidence, run_sql, uploaded_db],
         outputs=[sql, rows, status, schema, reasoning],
     )
-    # Refresh the schema map + raw DDL for whichever database is selected.
+    # Preview rows when the user picks a table.
+    table_dropdown.change(
+        browse_table, inputs=[uploaded_db, table_dropdown], outputs=[browse_df]
+    )
+    # Refresh the schema map, raw DDL, and table browser for the selected database.
     for trigger in (uploaded_db.change, demo.load):
         trigger(schema_map_html, inputs=[uploaded_db], outputs=[schema_map])
         trigger(show_schema, inputs=[uploaded_db], outputs=[schema])
+        trigger(refresh_browser, inputs=[uploaded_db], outputs=[table_dropdown, browse_df])
 
 
 ensure_sample_db()