The role of useunicode=true&characterencoding=utf-8 in MySQL connection URL

The purpose of the addition is to specify the encoding and decoding format of the characters.             

For example: The MySQL database uses GBK encoding, and the project database uses UTF-8 encoding. If Useunicode=true&characterencoding=utf-8 is added at this time, then there are two aspects of the function:

1. When data is stored:

When storing the project data, the database decodes the data into bytecode using the UTF-8 format, and then the decoded bytecode is reused in the database using the GBK encoding.

2. When data is taken:

When fetching data from the database, the database will first decode the data in the database into bytecode in GBK format, then encode the decoded bytecode again in UTF-8 format, and then return the data to the client.

NOTE: When you configure Database utl in an XML configuration file, to use the & escape character is also & For example:

<name= "url"  value= "Jdbc:mysql://localhost:3306/email?" Useunicode=true&amp;characterencoding=utf-8 "/>

Special characters commonly used in HTML:

Most commonly used character entities (Character entities)

Show results	Description	Entity Name	Entity number
	Show a space	 	& #160;
<	Less than	&lt;	& #60;
>	Greater than	&gt;	& #62;
&	& Symbols	&amp;	& #38;
"	Double quotes	&quot;	& #34;

Other commonly used character entities (Character entities)

Show results	Description	Entity Name	Entity number
©	Copyright	©	& #169;
®	Registered trademarks	®	& #174;
X	Multiplication sign	×	& #215;
÷	Division Sign	÷	& #247;

The role of useunicode=true&characterencoding=utf-8 in MySQL connection URL