From f70e35c9bbc0d5803bc0aee572b894a8b21ac41e Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Sun, 14 Jul 2019 11:58:40 -0700
Subject: [PATCH] Added table.rows_where(where, args) method

---
 docs/python-api.rst |  7 +++++++
 sqlite_utils/db.py  |  8 +++++++-
 tests/test_get.py   | 22 ++++++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 tests/test_get.py

diff --git a/docs/python-api.rst b/docs/python-api.rst
index 210939f..0cc5007 100644
--- a/docs/python-api.rst
+++ b/docs/python-api.rst
@@ -65,6 +65,13 @@ To iterate through dictionaries for each of the rows in a table, use ``.rows``::
     {'id': 1, 'age': 4, 'name': 'Cleo'}
     {'id': 2, 'age': 2, 'name': 'Pancakes'}
 
+You can filter rows by a WHERE clause using ``.rows_where(where, where_args)``::
+
+    >>> db = sqlite_utils.Database("dogs.db")
+    >>> for row in db["dogs"].rows_where("age > ?", [3]):
+    ...     print(row)
+    {'id': 1, 'age': 4, 'name': 'Cleo'}
+
 Creating tables
 ===============
 
diff --git a/sqlite_utils/db.py b/sqlite_utils/db.py
index 3a44cb4..9b179ac 100644
--- a/sqlite_utils/db.py
+++ b/sqlite_utils/db.py
@@ -365,9 +365,15 @@ class Table:
 
     @property
     def rows(self):
+        return self.rows_where()
+
+    def rows_where(self, where=None, where_args=None):
         if not self.exists:
             return []
-        cursor = self.db.conn.execute("select * from [{}]".format(self.name))
+        sql = "select * from [{}]".format(self.name)
+        if where is not None:
+            sql += " where " + where
+        cursor = self.db.conn.execute(sql, where_args or [])
         columns = [c[0] for c in cursor.description]
         for row in cursor:
             yield dict(zip(columns, row))
diff --git a/tests/test_get.py b/tests/test_get.py
new file mode 100644
index 0000000..75ddaef
--- /dev/null
+++ b/tests/test_get.py
@@ -0,0 +1,22 @@
+import pytest
+
+
+@pytest.mark.parametrize(
+    "where,where_args,expected_ids",
+    [
+        ("name = ?", ["Pancakes"], {2}),
+        ("age > ?", [3], {1}),
+        ("name is not null", [], {1, 2}),
+        ("is_good = ?", [True], {1, 2}),
+    ],
+)
+def test_rows_where(where, where_args, expected_ids, fresh_db):
+    table = fresh_db["dogs"]
+    table.insert_all(
+        [
+            {"id": 1, "name": "Cleo", "age": 4, "is_good": True},
+            {"id": 2, "name": "Pancakes", "age": 3, "is_good": True},
+        ],
+        pk="id",
+    )
+    assert expected_ids == {r["id"] for r in table.rows_where(where, where_args)}