Django filter(icontains).extra 产生错误的 SQL 语法（无引号）答案

【问题标题】：Django filter(icontains).extra produces wrong SQL syntax (no quotes)Django filter(icontains).extra 产生错误的 SQL 语法（无引号）
【发布时间】：2014-09-12 06:02:19
【问题描述】：

我正在尝试构建自定义查询，并希望在 filter() 之后应用 .extra()。声明如下：

V.objects.filter(v_id__product__icontains=name)

现在它生成了有效的 SQL，但是，它的名称周围没有引号：

WHERE `v_id`.`product` LIKE %xxx%

但是当我添加 .extra() 语句时：

V.objects.filter(id__product__icontains=name).extra(where=[concat_str],params=[version,'%','%'])

，查询无效，因为 %xxx% 前后没有引号：

WHERE `v_id`.`product` LIKE %xxx% AND 'yyy' LIKE CONCAT('%',version,'%')

我只需要在 %xxx% 周围添加单引号，以使其有效：

WHERE `vulnerabilities_cpeid`.`product` LIKE '%xxx%' AND 'yyy' LIKE CONCAT('%',version,'%')

但是，我只是不知道如何强制 Django 在使用 icontains 时将 %xxx% 放入单引号中。任何帮助表示赞赏。提前谢谢你。

完整的追溯：

INFO 2014-07-21 11:33:55,515 views: SELECT `vulnerabilities_vulnerability`.`identifier` FROM `vulnerabilities_vulnerability` INNER JOIN `vulnerabilities_vulnerability_cpe_id` ON (`vulnerabilities_vulnerability`.`id` = `vulnerabilities_vulnerability_cpe_id`.`vulnerability_id`) INNER JOIN `vulnerabilities_cpeid` ON (`vulnerabilities_vulnerability_cpe_id`.`cpeid_id` = `vulnerabilities_cpeid`.`id`) WHERE (`vulnerabilities_cpeid`.`product` LIKE %accountsservice%  AND '0.6.15-2ubuntu9.7' LIKE CONCAT('%',version,'%'))
ERROR 2014-07-21 11:33:55,517 django.request: Internal Server Error: /vulndb/inventory/
Traceback (most recent call last):
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/django/core/handlers/base.py", line 111, in get_response
    response = callback(request, *callback_args, **callback_kwargs)
  File "/home/sapegin/vulndb_mercurial/vulndb/vulndb/vulnerabilities/views.py", line 1650, in inventory
    if ((vulnerabilities is not None) and (vulnerabilities.count() > 0)):
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/django/db/models/query.py", line 351, in count
    return self.query.get_count(using=self.db)
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/django/db/models/sql/query.py", line 418, in get_count
    number = obj.get_aggregation(using=using)[None]
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/django/db/models/sql/query.py", line 384, in get_aggregation
    result = query.get_compiler(using).execute_sql(SINGLE)
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/django/db/models/sql/compiler.py", line 818, in execute_sql
    cursor.execute(sql, params)
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/django/db/backends/util.py", line 40, in execute
    return self.cursor.execute(sql, params)
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/django/db/backends/mysql/base.py", line 119, in execute
    return self.cursor.execute(query, args)
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/MySQL_python-1.2.4-py2.6-linux-x86_64.egg/MySQLdb/cursors.py", line 201, in execute
    self.errorhandler(self, exc, value)
  File "/home/sapegin/vulndb_mercurial/vulndb/HANA/PYTHON/Python/lib/python2.6/site-packages/MySQL_python-1.2.4-py2.6-linux-x86_64.egg/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
DatabaseError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '0.6.15-2ubuntu9.7'' LIKE CONCAT(''%'',version,''%''))' at line 1")
ERROR 2014-07-21 11:33:55,517 django.request: Internal Server Error: /vulndb/inventory/

【问题讨论】：

Django 之后会在%xxx% 周围加上引号，你在.query 中看不到这一点。你得到什么错误？
我得到 "DatabaseError: (1064, "You have an error in your SQL syntax;..."。如果我复制使用 .query 生成的字符串，请手动添加引号，然后在mysql 控制台，我没有收到任何错误。
请在问题中包含完整的回溯。谢谢。

标签： python sql django django-orm django-filter

【解决方案1】：

我敢打赌，错误是您的 .extra 调用参数中有额外的引号。删除 %s 周围的引号，看看是否能解决问题。

【讨论】：

【解决方案2】：

在 Django 中，DatabaseWrapper 会自动添加引号。 'icontains' 运算符被转换为'icontains': 'LIKE %s'，其中%s 将被替换为在搜索词前后用% 符号连接的字符串。

在内部，Django 将使用quote_name 函数来做引号。

def quote_name(self, name):
    if name.startswith("`") and name.endswith("`"):
        return name # Quoting once is enough.
    return "`%s`" % name

对于您的用例，原始查询可能是更好的解决方案：

Model.objects.raw('Select .... FROM .... WHERE ....', params=None, translations=None)

看看：https://docs.djangoproject.com/en/dev/topics/db/sql/

我认为 alecxe 是对的，.query 中的调试还不够。

【讨论】：