text char

Charvarcharvarchar2 differences: 1. the length of CHAR is fixed, while the length of VARCHAR2 can be changed. For example, the storage string "abc", for CHAR (20 ), it indicates that the characters you store will occupy 20 bytes (including 17 null

MySQL Char,varchar,text,blob is a few links but there are a lot of different types of fields, which is the basis of MySQL, but the foundation did not learn, bad to fill.Let's summarize briefly:Char: fixed length , maximum 255 charactersVARCHAR:

ntextThe maximum length of a variable-length Unicode data is 230-1 (1,073,741,823) characters. The storage size is twice times the number of characters entered (in bytes). The synonym of ntext in SQL-92 is national text.ntext The data is stored in

Char varchar varchar2 the difference http://blog.csdn.net/honglei_zh/article/details/7172538Difference:1. The length of the char is fixed, and the length of the VARCHAR2 is changeable, for example, storing the string "abc", for Char (20), which

1. CHAR. It is very convenient for CHAR to store fixed-length data, and the indexing efficiency of CHAR fields is high. For example, if char (10) is defined, no matter whether the data you store reaches 10 bytes, it takes up 10 bytes of space. If

Ext.: http://blog.csdn.net/jackychu/article/details/4183118Http://www.cnblogs.com/jhxk/articles/1633578.htmlMany developers in the database design often do not have much to consider char, varchar type, some do not pay attention to, because the

CharChar is fixed-length, that is, when you enter a character that is less than the number you specify, char (8), the character you enter is less than 8 o'clock, and it will then fill the empty value back. When you enter a character that is larger

The length of a char column is fixed to the length declared during table creation. The length can be any value from 0 to 255. When saving CHAR values, fill in spaces on the right of them to reach the specified length. When the CHAR value is

Program Demonstration: Test Environment Devc ++ Code # Include Using namespace std; Main () { Char * c1 = "abc "; Char c2 [] = "abc "; Char * c3 = (char *) malloc (3 ); C3 = "abc "; Printf ("% d % s \ n", & c1, c1, c1 ); Printf ("% d % s \ n", & c2,

Where can I find the source? Char * c = "ABC" and char C [] = "ABC", where the former changesThe program crashes, and the latter is completely correct.Program Demonstration:Test Environment devc ++Code# Include Using namespace STD;Main (){Char * C1 =