postgres enum type

In actual development, in database table design, we are often used to using an int type state field to represent the data status. This field is very convenient to represent the status of this data, however, it is unwilling to create a foreign key table for this state field to explain the state. (There may be many fields in the status of this type of table. Here is an example) We generally treat this state

("name", a), the method PutExtra (String, parcelable) is ambiguous for the type Intent's fault, why?Since the enum itself implements the serializable interface, the Enum class is written in the source code:[Java]View Plaincopy Public abstract class Enumextends Enumimplements Serializable, comparable ...... } Then your MyEnum class implement

C # Enumeration type conversion string enum to String Enumeration types are value types. System.Enum is an abstract class (abstract class) in which all enumerated types inherit directly from it and, of course, all of its members. All value types are descendants of System.ValueType, enumeration types are no exception, enum types inherit directly from System.Enu

#if (__cplusplus __cplusplus >= 201103L (__has_extension (cxx_strong_enums) | | __has_feature (objc_fixed_enum))) | | (!__cplusplus __has_feature (objc_fixed_enum)) #define NS_ENUM (_type, _name) ENUM _name: _type _name; Enum _name: _type #if (__cplusplus) #define Ns_options (_type, _name) _type _name; Enum: _type #else #define Ns_options (_typ

We usually have an int type field, with different numbers, meaning different meanings, in order to make the program more readable and make the UI more convenient, it is a good thing to use Enum to represent the field value.For example, there is a sex field, an int type, a gender, 1 is a male, 2 is a female, then the value of the database is 1 or 2, but when we sh

Today, when I was studying the enum, I tried to import the enum using the following code but failed. from Import EnumReport the following errorAt first I was very surprised to know that any language I am currently in touch with, as long as the support enum must be included in the language of the basic package, and some languages even directly do not need to intro

In practical programming, some data is often limited, only a very small number of integers, and preferably a name for each value to facilitate the use of subsequent code, such as one weeks only seven days, only 12 months a year, a class has six courses each week. For example, seven days a week, we can use the #define command to specify a name for each day: #include #define SAT 6 #define SUN 7 int main () { int day; scanf ("%d", day); Switch (day) {case mon:puts ("Monday"

row in Set (0.00 sec) The following test enum Mysql> Select concat (Round (sum (data_length/1024/1024), 3), ' MB ') as Data_size,-Concat (Round (sum (max_data_length/1024/1024), 3), ' MB ') as Max_data_length,-Concat (Round (sum (data_free/1024/1024), 3), ' MB ') as Data_free,-Concat (Round (sum (index_length/1024/1024), 3), ' MB ') as Index_lengthFrom Information_schema.tables where table_name= ' userinfo ';+-----------+-----------------+-----------

Enum type converted to int typeCases:1 Public enum Gender 2 {3 male,4 female 5} 6 7 Gender Gender =8int a = Gender; 9 Console.WriteLine (a);Input Result:0There is also a feature:1 Public enum Gender 2 {3 male =5,4 female 5}67 Gender Gender =8int a = Gender; 9 Console.WriteLine (a);Input Result:51 Gender Gender =2int

An enumeration is a data type, not a constructed type, which should not be decomposed into any basic type 1 The general form of the enumeration type declaration: Enum Enum type name

encapsulated, and most importantly, it will be checked during compilation. Because Java is a strong type, that is, during compilation, the compiler checks all prototype and parameter types. If the type is incorrect and there is no forced transformation, A compilation error is reported, except for the automatic transformation supported by the compiler. For example, if an int is required, and the input param

savedInstanceState ){Super. onCreate (savedInstanceState );SetContentView (R. layout. linearlayout_test );LinearLayout one = (LinearLayout) findViewById (R. id. linearlayout_test_1 );One. setOrientation (2012 );LinearLayout two = (LinearLayout) findViewById (R. id. linearlayout_test_2 );Two. setOrientation (Integer. MAX_VALUE );LinearLayout three = (LinearLayout) findViewById (R. id. linearlayout_test_3 );Three. setOrientation (Integer. MIN_VALUE );}} Use E