postgres enum type

Objective In daily programming, there are often such "datasets," whose values are stable in the program, and the elements in the dataset are finite. For example, from Monday to Sunday, seven data elements constitute a week of "data sets", Four seasons of four data elements constitute the "dataset". How do you better use these "datasets" in Java? So the enumeration came in handy. An enumeration is actually a type, like int, char, which restricts inpu

Definition of enum typeAn enumeration type (enumeration) is a derived data type in C + +, which is a collection of user-defined enumeration constants.Definition Format : Enumeration type is defined in the following format:Enum which The keyword enum--indicates that

An enum is an enumeration type, which in effect defines a set of values, and the value of the enum definition data type can only be one of this set of values.In real life, a lot of problems are related to this. There are only two men and women in gender, seven days a week, and only 12 values for the month.A value of se

In the development process, some state representation is used to the enumeration type, so how to bind the enum type directly to ListControl (DropDownList) is the subject of this time, the nonsense is not much to say, the direct code:First look at the tool class code: /// ///binding to a generic class for a ListControl control by an enumeration

How enum enum types are defined and some usage#include 　　Definition of enum enum type

Enumeration understands:The enumeration type is part of the new feature in Java 5, which is a special type of data that is special because it is a class type but has some special constraints over the class type, butThe existence of these constraints also creates the simplicity, security, and convenience of enumeration

The enumeration is defined in MSDN as: The enum keyword is used to declare an enumeration, a unique type consisting of a set of named constants called an enumerated list of columns. Each enumeration type has an underlying type, which can be any integral type other than char.

Some enumeration types are defined in the recent project, and you need to pass the enumerated key values to the front end for making the drop-down menu.1, first defines the enumeration type Public enum int {Sick leave = 1,Leave = 2,Marriage leave = 3,Maternity leave = 4,Bereavement = 5 }Here I created a new console application that looked at the output effect,public static void Main (string[] args

C Language Programming Advanced _ First week: Data type: integer type, floating-point type, enum type1.0 Data Types1.1 Integer type1.2 Floating-point types1.3 Logical Types1.4 Type conversions and conditional operations1.0 Data Types1 integerschar (%c), short, int (%d), long

/* The Stamp* When you want a group of numbers to represent a particular meaning, and you want to be safe, you can read strong.** The type is used as an integral type in its own way.* The type can be: Byte,sbyte,short,ushort,int,uint,long,ulong of the child* If no type is specified, the

In the database we typically use integers or strings to represent enumeration values (some databases (such as MySQL) have enumeration types themselves), and an integer or string representation of an enumeration in an entity object when using Hibernate is less friendly. Let's just think of this. Define two properties of an entity object @Entity public class User { .... public Integer type; //0:individual

First, IntroductionJSON is a full copy of the input, and then parse it, so it preserves the input spaces, repetition keys, and order. The JSONB is a binary that is saved after parsing the input, and it removes unnecessary spaces and duplicate keys when parsing, and the order and input may not be the same. Make time without parsing again.Summarize: . JSON jsonb Save Fast Slow Take Slow Fast Ii. Practice

128.0.0.0/16 128.0/16 128.1.2 128.1.2.0/24 128.1.2/24 10.1.2 10.1.2.0/24 10.1.2/24 10.1 10.1.0.0/16 10.1/16 10 10.0.0.0/8 10/8 10.1.2.3/32 10.1.2.3/32 10.1.2.3/32 2001:4f8:3:ba::/64 2001:4f8:3:ba::/64 2001:4f8:3:ba::/64 2001:4f8:3:ba:2e0:81ff:fe22:d1f1/128 2001:4f8:3:ba:2e0:81ff:fe22:d1f1/128 2001:4f8:3:ba:2e0:81ff:fe22

I recently used hibernate to map enumeration types. in MySQL databases, if the type of the enumeration type attribute is not configured in the hibernate map file, hibernate will map the enum type to the tinyblob type by default, which is very embarrassing. It seems that it w

Transferred from: http://blog.csdn.net/yufenghyc/article/details/45869509--1 Examplepostgres=# Select 1/4;? column?----------0(1 row)In PG If you want to do division and want to keep decimals, the method above does not work, because the "/" Operation results are rounded, and the fractional part is truncated.--2 Type Conversionspostgres=# Select round (1:: Numeric/4:: Numeric,2);Round-------0.25(1 row)Note: After the

Q: In C #, how do we express enumeration types? A: You can use the enum keyword (keyword) to declare an enumeration type (enum type ): //Code#01 publicenumAlignment { Left, Center, Right } --------------------------------------------------------------------------------Q: C # Is the enumerated

All I have described above are value types, so much so that I summarize the following what is called value type. Simply put, this type of variable stores the contained values directly. Here we are relative to the C language string, char ch[6] = "HC666"; The teacher said here is actually using CH to refer to the "HC666" address, access to the data through the address. String is the same, so strings in C # ar

JAVA enum Enumeration type, javaenum Enumeration type 1. Definitions of enumeration types: 1) The Enumeration type can be a separate class file. /** * This enum is declared in the Season.java file.*/public enum Season { WINTER,

) is obviously not, and the compilation is passed, and what happens at runtime is unknown to us. This obviously does not conform to the type safety of Java programs.Next, let's consider the readability of this pattern. In most cases where enumerations are used, I need to be convenient to get string expressions of enumerated types. If you print an int enumeration constant, what we see is a set of numbers, which is of little use. We might think of using

The enum type is defined as follows: Public Enum Interactivetype {Nothing = 1 , // Do nothing Email = 2 , // Sent by email Jiwai = 3 // Sent back via SMS (updated via API, and then sent back through the follow function) } If we want to convert the string "email" or number to the