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Template tag to dump database query info

Author:
pryankster
Posted:
April 6, 2007
Language:
Python
Version:
.96
Score:
6 (after 6 ratings)

This snippet introduces two tags: {%dbinfo%} and {%dbquerylist%}. The {%dbinfo%} tag returns a string with the # of database queries and aggregate DB time. The {%dbquerylist%} tag expands to a set of <LI> elements containing the actual SQL queries executed. If settings.TEMPLATE_DEBUG is False, both tags return empty strings.

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rom django.template import Node
from django.template import Library
from django.conf import settings
import django.db as db
import re
from django.utils.html import escape

register = Library()

class DbInfoNode(Node):
    def __init__(self):
        pass

    def __repr__(self):
        return "<DbInfoNode>"

    def render(self, context):
        if not settings.TEMPLATE_DEBUG:
            return ""
        secs = 0.0
        for s in db.connection.queries:
            secs += float(s['time']);
        return str("%d queries, %f seconds" % (len(db.connection.queries), secs)
)

def do_dbinfo(parser, token):
    return DbInfoNode()
do_dbinfo = register.tag('dbinfo', do_dbinfo)

class DbQueryListNode(Node):
    def __init__(self):
        pass

    def __repr__(self):
        return "<DbQueryListNode>"

    def render(self, context):
        if not settings.TEMPLATE_DEBUG:
            return ""
        s = ""
        for q in db.connection.queries:
            s += "<li>" + escape(q["sql"]) + "</li>\n"
        return s

def do_dbquerylist(parser, token):
    return DbQueryListNode()

do_dbquerylist = register.tag('dbquerylist', do_dbquerylist)

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