choice

问题 I'm trying to make a field with limited choices: Action_Types=( ('0','foo'), ('1','bar'), ) class Foo(models.Model): myAction=models.CharField(max_length=1,choices=Action_Types) def __unicode__(self): return '%d %s'%(self.pk,self.myAction) However, when I was trying to insert content violating the rules, it succeeded without any error or warning messages (with "manage.py shell"). It seems any text of any length can be put into this field. I'm using SQLite3 as the backend. Is it supposed to be

问题 I'm trying to make a field with limited choices: Action_Types=( ('0','foo'), ('1','bar'), ) class Foo(models.Model): myAction=models.CharField(max_length=1,choices=Action_Types) def __unicode__(self): return '%d %s'%(self.pk,self.myAction) However, when I was trying to insert content violating the rules, it succeeded without any error or warning messages (with "manage.py shell"). It seems any text of any length can be put into this field. I'm using SQLite3 as the backend. Is it supposed to be

问题 In what situations it is preferred to return an object instead of just modifying an object passed to that function by reference? How do I know which one should I pick? Actually, the question is if there are things I wouldn't be able to do without the ability to return an object from function, but instead only modifying objects passed by reference. 回答1: The main pragmatic difference between TYPE function () ; and void function (TYPE &value) ; is that the former can be used in expressions. a =

问题 Is there any way with Symfony to render a <select> form type with disabled options, based on the truthyness of the given choices options ? I saw this thread (thanks to DonCallisto) about disabling choice expanded options ; However I do not want to have an expanded choice. I would like to keep a select element, with disabled options . $builder->add('list', 'choice', array( 'choices' => array( array( 'value' => 1, 'label' => '1', 'disabled' => false ), array( 'value' => 2, 'label' => '2',

问题 I'm trying to create a batch file that performs different 'choice' command based on the version of Windows being executed on. The choice command's syntax is different between Windows 7 and Windows XP. Choice command returns a 1 for Y and 2 for N. The following command returns the correct error level: Windows 7: choice /t 5 /d Y /m "Do you want to automatically shutdown the computer afterwards " echo %errorlevel% if '%errorlevel%'=='1' set Shutdown=T if '%errorlevel%'=='2' set Shutdown=F

问题 This question already has answers here : GROUP BY behavior when no aggregate functions are present in the SELECT clause (8 answers) Closed 5 years ago . If I have an SQL query like this one: SELECT playerno,town FROM players GROUP BY town In this case, the server will return lets say one town, and for playerno, it will return one value, even if there were multiple values in the database. My question is, which value will be chosen? Is the choice made randomly, or will it take the first result,

问题 Is it possible to distinct xs:choices in xsd by using fixed values? I have a simple type: <xs:simpleType name="datatypeCategory"> <xs:restriction base="xs:string"> <xs:enumeration value="SIMPLE"/> <xs:enumeration value="COMPLEX"/> <xs:enumeration value="COLLECTION"/> </xs:restriction> </xs:simpleType> And what I want to achieve is <xs:element name="datatype"> <xs:complexType> <xs:choice> <xs:sequence> <xs:element id="category" type="datatypeCategory" fixed="SIMPLE"/> <!-- some fields specific

问题 I need to check if visitor is first time on website and show block with country choice(stores). Then I need to save visitor choice in cookies(I just think that it is right to save it in cookies). Maybe someone did that and\or can help? Thanks. 回答1: When the user lands on the page check if a cookie is set, if it is then redirect to the store view based on the cookie value. I'm pretty new to magento so there is probably a better way to do this, but i needed something similar myself. I had a

问题 I have the following XML Schema <xsd:complexType name="SimpleThing"> <xsd:choice maxOccurs="unbounded"> <xsd:group ref="simpleContent" /> </xsd:choice> </xsd:complexType> <xsd:complexType name="ExtendedThing"> <xsd:complexContent> <xsd:extension base="SimpleThing"> <xsd:choice maxOccurs="unbounded"> <xsd:element name="qux" /> </xsd:choice> </xsd:extension> </xsd:complexContent> </xsd:complexType> <xsd:group name="simpleContent"> <xsd:choice> <xsd:element name="foo" /> <xsd:element name="bar"

问题 I have followed the instructions in section 13.5.1 of R for Marketing Research and Analytics , transforming a set of data into the required format and running the following commands. I want the part worths to be calculated between the levels of an attribute, i.e., that sum of the levels per attribute should equal zero. Could anyone help me with this? > library(bayesm) > library(MASS) > library(lattice) > library(Matrix) > library(ChoiceModelR) > Test <- data.frame(ChoiceData) > dput(Test)