[Database Mybatis] The nomenclature camel case nomenclature Hungarian nomenclature underscore nomenclature database table field name is inconsistent with the member variable name of the class as to use the resultMap alias in mybatis

Nomenclature

Hump ​​nomenclature

Big Hump Nomenclature

Purpose: Commonly used in class names, function names, attributes, and namespaces.
Little camel case means: Pascal nomenclature of the first letter of a word
is big camel case nomenclature

AaBaCcDd
MyCompanyName

Little Hump Nomenclature

Purpose: Variables are generally identified by the little hump method.
The little hump method means: except for the first word, capitalize the first letter of other words

aaBbCcDd
myCompanyName

Hungarian nomenclature

Used to determine the type of a variable. The
basic principle is: variable name = attribute + type + object description

int iMyAge; # “i”: int
char cMyName[10]; # “c”: char
float fManHeight; # “f”: float

Underscore nomenclature

Each logical breakpoint in the function name is marked by an underscore

my_company_name
aa_bb_cc_dd

The database table field name is inconsistent with the member variable name of the class

It can be seen that the name of the database is aaa_bbb type, and the member variable name of the class is aaaBbb type, the two are inconsistent

As alias (more troublesome, write out all table members)

Change the table name of the database using as to the member variable name of the class

 <select id="findAll" resultType="company">
select
	id,
	name ,
	expiration_date as expirationDate ,
	address,
	license_id as licenseId  ,
	representative ,
	phone  ,
	company_size as companySize  ,
	industry  ,
	remarks ,
	state,
	balance ,
	city
from ss_company
    </select>

Use resultMap in mybatis

 <resultMap id="companyMap" type="company">
         <id column="id" property="id"/>
         <result  column="expiration_date" property="expirationDate"/>
         <result  column="license_id" property="licenseId"/>
         <result  column="company_size" property="companySize"/>
    </resultMap>
    <select id="findAll" resultMap="companyMap">
        select
            *
        from ss_company
    </select>