MySQL Django：创建索引：非唯一，多列
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/1578195/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Django: create Index: non-unique, multiple column
提问by jbastos
Given the following model, I want to index the fields (sequence,stock)
鉴于以下模型，我想索引字段（序列，库存）
class QuoteModel(models.Model):
quotedate = models.DateField()
high = models.FloatField() #(9,2) DEFAULT NULL,
low = models.FloatField() #(9,2) DEFAULT NULL,
close = models.FloatField() #(9,2) DEFAULT NULL,
closeadj = models.FloatField() #(9,2) DEFAULT NULL,
volume = models.IntegerField() #(9,2) DEFAULT NULL,
stock = models.IntegerField(db_index=True) #(9,2) DEFAULT NULL,
open = models.FloatField() #(9,2) DEFAULT NULL,
sequence = models.IntegerField() #(9,2) DEFAULT NULL,
This index should be non-unique - in mysql it should be something like:
这个索引应该是非唯一的——在 mysql 中它应该是这样的：
create index ndx_1 on model_quotemodel(sequence,stock);
The only Django workaround I know of is creating an "sql" file that will be executed by django upon table creation. So, I created a "stockmodel.sql" containing the following query (same as above:)
我所知道的唯一 Django 解决方法是创建一个“sql”文件，该文件将由 django 在创建表时执行。所以，我创建了一个包含以下查询的“stockmodel.sql”（同上：）
create index ndx_1 on model_quotemodel(sequence,stock);
Is there any "cleaner" way of doing it?
有什么“更干净”的方法吗？
采纳答案by excieve
As of Django 1.5, you can use the Meta.index_togetheroption:
从 Django 1.5 开始，您可以使用Meta.index_together选项：
class QuoteModel(models.Model):
# ... fields ...
class Meta:
index_together = [
("sequence", "stock"),
]
(note: the original answer from 2009 said it was not possible to index multiple fields; it has since been replaced)
（注意：2009 年的原始答案说不可能索引多个字段；它已被替换）
回答by Ivan Virabyan
There is a ticket for this feature. Take a look http://code.djangoproject.com/ticket/5805
此功能有一张票。看看http://code.djangoproject.com/ticket/5805
You may apply the patch from this ticket yourself.
您可以自己应用此票证中的补丁。
UPDATE
更新
It's now in Django: https://docs.djangoproject.com/en/1.5/ref/models/options/#django.db.models.Options.index_together
它现在在 Django：https: //docs.djangoproject.com/en/1.5/ref/models/options/#django.db.models.Options.index_together
回答by George Lund
To follow on from the accepted answer, if you are using South, you can easily add a composite key as follows:
从接受的答案继续，如果您使用South，您可以轻松添加复合键，如下所示：
manage.py schemamigration your_app_name name_for_migration --add-index ModelName.first_field_in_index
manage.py schemamigration your_app_name name_for_migration --add-index ModelName.first_field_in_index
You can then edit the generated migration file to add the additional fields into the one index (you'll see it's just a list of field names that's needed).
然后，您可以编辑生成的迁移文件以将其他字段添加到一个索引中（您将看到它只是所需的字段名称列表）。
Don't forget to update the reverse migration as well as the forward one.
不要忘记更新反向迁移和正向迁移。
回答by cashmere
It is index_together in django 1.5
它是 django 1.5 中的 index_together
See here https://docs.djangoproject.com/en/dev/ref/models/options/#index-together
请参阅此处https://docs.djangoproject.com/en/dev/ref/models/options/#index-together
回答by craesh
unique_togethermight be what you are looking for. Just put it in your Metaclass inside your model.
unique_together可能是你正在寻找的。只需将它Meta放在模型中的类中即可。
回答by Lingster
I just wanted to add that as of Django 1.11 there is a new feature, Options.indexes, which will allow you to specify the indexes to create:
我只想补充一点，从 Django 1.11 开始，有一个新功能 Options.indexes，它允许您指定要创建的索引：
回答by Samuel Dauzon
The index_togetherfeature could be deprecated in the futur.
该index_together功能可以在未来的危机被弃用。
You should use indexesoption instead of index_together.
您应该使用索引选项而不是index_together。
Example of indexesoption :
索引选项示例：
from django.db import models
class Customer(models.Model):
first_name = models.CharField(max_length=100)
last_name = models.CharField(max_length=100)
class Meta:
indexes = [
models.Index(fields=['last_name', 'first_name']),
models.Index(fields=['first_name'], name='first_name_idx'),
]
