Adding view to explain SQL passed in via query string. Hopefully this is

database backend agnostic.  Next up is connecting this with the SQL panel via
AJAX.

3 files changed, 61 insertions, 0 deletions

diff --git a/debug_toolbar/templates/debug_toolbar/panels/sql_explain.html b/debug_toolbar/templates/debug_toolbar/panels/sql_explain.html
new file mode 100644
index 0000000..757d43f
--- /dev/null
+++ b/debug_toolbar/templates/debug_toolbar/panels/sql_explain.html
@@ -0,0 +1,25 @@
+<h3>SQL Explained</h3>
+<dl>
+	<dt>Executed SQL</dt>
+	<dd><pre>{{ sql|wordwrap:80 }}</pre></dd>
+	<dt>Time</dt>
+	<dd>{{ time }} ms</dd>
+</dl>
+<table>
+	<thead>
+		<tr>
+			{% for h in headers %}
+				<th>{{ h|upper }}</th>
+			{% endfor %}
+		</tr>
+	</thead>
+	<tbody>
+		{% for row in result %}
+			<tr class="{% cycle 'row1' 'row2' %}">
+				{% for column in row %}
+					<td>{{ column|escape }}</td>
+				{% endfor %}
+			</tr>
+		{% endfor %}
+	</tbody>
+</table>
diff --git a/debug_toolbar/urls.py b/debug_toolbar/urls.py
new file mode 100644
index 0000000..24d4b12
--- /dev/null
+++ b/debug_toolbar/urls.py
@@ -0,0 +1,6 @@
+from django.conf.urls.defaults import *
+
+urlpatterns = patterns('',
+    # EXPLAIN SQL via AJAX
+    url(r'explain/$', 'debug_toolbar.views.explain', name='explain_sql'),
+)
diff --git a/debug_toolbar/views.py b/debug_toolbar/views.py
new file mode 100644
index 0000000..5bdf450
--- /dev/null
+++ b/debug_toolbar/views.py
@@ -0,0 +1,30 @@
+import simplejson
+from django.db import connection
+from django.shortcuts import render_to_response
+from debug_toolbar.panels.sql import reformat_sql
+
+def explain(request):
+    """
+    Returns the output of the SQL EXPLAIN on the given query.
+    
+    Expected GET variables:
+        sql: urlencoded sql with position arguments
+        params: JSON encoded parameter values
+        time: time for SQL to execute passed in from toolbar just for redisplay
+    """
+    sql = request.GET.get('sql', '')
+    if sql.lower().startswith('select'):
+        params = simplejson.loads(request.GET.get('params', ''))
+        cursor = connection.cursor()
+        cursor.execute("EXPLAIN %s" % (sql,), params)
+        headers = [d[0] for d in cursor.description]
+        result = cursor.fetchall()
+        cursor.close()
+        context = {
+            'result': result,
+            'sql': reformat_sql(cursor.db.ops.last_executed_query(cursor, sql, params)),
+            'time': request.GET.get('time', 0.0),
+            'headers': headers,
+        }
+        return render_to_response('debug_toolbar/panels/sql_explain.html', context)
+        
\ No newline at end of file