two types of database

First, the basic data type:byte: Smallest data type in Java, 8 bits in memory (bit), 1 bytes, value range -128~127, default value 0short: Shorter integer, 16 bits in memory, 2 bytes, range -32768~32717, default value 0int: integral type, used to store integers, 32 bits, 4 bytes, value range -2147483648~2147483647, default value 0Long: integer, 64 bits in memory, 8 bytes -2^63~2^63-1, default 0Lfloat: floating point, 32 bits in memory, 4 bytes, for storing a number with a decimal point (the diffe

PHP generates three types of code instances for short URLs, and php generates three types of instances. The short URL service may be no longer unfamiliar to many of my friends. Now, there are many application modes in most Weibo, mobile phone email reminders and other places, and they occupy a certain market. It is estimated that many of our friends are using the service now. I have read Sina's short Connec

The most important four types of tables in DedeCMS and four types of tables in dedecms Topic (category): dede_arctype (dede Database Designer thinks: No matter what data you store (software, product, movie...) should belong to a certain topic (type )) Content master table: dede_archives (the zhimeng Database Designer

(From: http://book.csdn.net/bookfiles/933/10093329328.shtml) Parsing: CLR supports two types: Value Type and reference type. In the words of Jeffrey Richter (author of CLR via C #), "I don't understand the differences between reference types and value types.ProgramThe clerk willCodeIntroduce weird traps and many performance problems ". This requires us to correctly understand and use the value type and re

Why to translateOne is in order to feel the best foreign technology community well-known bloggers high-quality articles, and secondly is to review the right. NET Technology Foundation supplements achieves the restudying effect, finally also is in order to exercise own English reading and writing ability. Because it is the first time to translate English article (Ah, forgive me this dish than, weak explosion!) , so there will certainly be a lot of problems (some of the sentence understanding is n

value typeattributes of value types:all value types of 1.c# are implicitly derived from System.ValueType. each value type and its base class:structure:struct (directly derived fromSystem.ValueType);Numeric Type:Integral type:ShortSystem.Int16),UShortSystem.UInt16),intSystem.Int32),UIntSystem.UInt32),LongSystem.Int64),ULongSystem.UInt64),SByte (alias of System.SByte),ByteSystem.Byte),Character type:CharSystem.Char);floating point type:FloatSystem.Singl

Differences and usage of the three Timer types in. NET and the use of. net timer types Recently, a program is executed on a regular basis on the WEB, and. NET has three different timers. So it's just research. The three timers are:// 1. Implement the timer for events triggered at user-defined intervals. This timer is most suitable for Windows Forms applications and must be used in Windows.System. Windows. F

Label:In MySQL database system, char and varchar are very common, and they are two very similar, are used to save relatively short string, such as saving the article title, message, email, user name and so on. The main difference between the two is the storage method:The Char column length is the length that is declared when the table is created and is fixed, and the length is limited to between 0 and 255. Generally in the

Content Guide• overview• What happens behind a variable when you declare it?• Heap and stack• Value types and reference types• What are value types and which are reference types?• Packing and unpacking• Packing and unpacking performance issuesI. OverviewThis article explains six important concepts: heap, stack, value t

ASP tutorial. NET C # value types and reference types detailed descriptionThere are two kinds of types in C #: Value types (values type) and reference types (reference type). Variables of value types directly contain their data,

Parsing: CLR supports two types: Value Type and reference type. In the words of Jeffrey Richter (author of CLR via C #), "programmers who do not understand the differences between reference types and value types will introduce code into weird traps and many performance problems ". This requires us to correctly understand and use the value type and reference type.

Content Guide Overview What happens behind a variable when you declare it? Heap and Stack Value types and reference types What are value types and which are reference types? Packing and unpacking Performance issues for boxing and unpacking I. OverviewThis article explains six impor

JNI/NDK Development Guide (iii) -- ing between JNI data types and Java data types, ndkjni Reprinted please indicate the source: http://blog.csdn.net/xyang81/article/details/42047899 When we call a Java native method, how does the parameter in the method pass to the local function in C/C ++? How are the parameters in the Java method converted from those in the C/C ++ function? I guess you should have relat

Why to translateOne is in order to feel the best foreign technology community well-known bloggers high-quality articles, and secondly is to review the right. NET Technology Foundation supplements achieves the restudying effect, finally also is in order to exercise own English reading and writing ability. Because it is the first time to translate English article (Ah, forgive me this dish than, weak explosion!) , so there will certainly be a lot of problems (some of the sentence understanding is n

The type of a valueThe basic types and reference types are mentioned earlier in the introduction of the data types of JS, but before we can say two types, let's look at the type of the variable's value. In ECMAScript, a variable can have two types of values, namely the origi

Content Guide Overview What happens behind a variable when you declare it? Heap and Stack Value types and reference types What are value types and which are reference types? Packing and unpacking Performance issues for boxing and unpacking I. OverviewThis article explains six impor

Content Guide Overview What happens behind a variable when you declare it? Heap and Stack Value types and reference types What are value types and which are reference types? Packing and unpacking Performance issues for boxing and unpacking I. OverviewThis article explains six impor

By default, there are only two types of C #:1. Nullable type: (Refers to nullable)Most of the objects, such as: dog dog = null;2. Non-nullable type:Basic value type, Boolean type, such as: int a = 0;//correctint a = null;//error3. Non-nullable methods to convert to nullable types:int? a = null; add a question mark after the non-nullable type "?" Can be converted to a nullable type .Tips:The int type is also nullable in the

Reprint Please specify Source: http://blog.csdn.net/xyang81/article/details/42047899When we call a Java native method. How are the parameters in the method passed to the C + + local function? The parameters in the Java method and the number of references in C + + functions. How do they convert between them? I guess you should have some doubts about that, too. Let's look at a sample first. Or take HelloWorld as an example:Helloworld.java:Package Com.study.jnilearn;class MyClass {}public class Hel

The CLR supports two types: reference types and value types. Reference types are always allocated from the managed heap. The new operator in C # returns the memory address of the object. Note Points for referencing objects: 1. Memory allocated from the managed heap 2, the heap on the allocation of objects, there