MySQL Character set explanation

first, what is a character set :

To put it simply, a character set is a set of corresponding relationships;

1, the current computer is built on the basis of binary system, binary is a numerical expression, that is, binary only expression "number", such as the decimal 3, in the binary

Can be written as 00000011;

2, however, in the real life compared to the "number" we use more is the "text"; then how to solve this problem (how to save the text)? But the question is not

They, they decided to settle in a compromise way, for example: Save ' a ' when I save a 0, save ' B ' When I save a 1, save ' a ' when I save a 2

Save ' B ' when I save a 3. So the whole correspondence becomes this.

Character---encoding

' A '-0

' B '--1

' A '-2

' B '--3

In this way we define a character set of only 4 characters, but we do not know where the low is in the character set compared to Gbk\utf8.

second, what is the collation :

1, the above content we have already defined a character set, with the character set some of the most basic operations may have done, such as: I want to know a character it is not ' a ' then

I just have to see if this character's code is 0, so it turns a character problem into a number problem, so the data equals (=), size (>,<), there is

A new meaning.

2. Do we have any shortage of this character set? such as: To do not distinguish between the case, then our previous =,<,> have come to spirit, we will also give this character set to add a new

Rules, as we can be rude here with the rule 1:0=2, 2:1=3, so it is possible to do a case-insensitive.

How can I specify a character set in MySQL :

1. mysql can specify the default character set at the instance level, the configuration item name: Character_set_server

2. You can specify a character set when creating a library

Create Database character set UTF8;

3. You can specify the table-level character set when creating a table

Create Table int  not NULL Primary Key varchar (4characterset  UTF8; -- specifies that the character set is UTF8 at the table level

4. You can specify when creating a table

Create Table int  not NULL Primary Key varchar (4characterset  UTF8); -- specifies that the character set of the name column is UTF8

　　　　　　

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MySQL Character set explanation