Spring boot learns six spring inheritance mybatis (based on annotations)

MyBatis provides a number of annotations such as: @InsertProvider, @UpdateProvider, @DeleteProvider and @SelectProvider, these are the methods of creating dynamic languages ​​and letting MyBatis execute these languages ​​using annotation-based mybatis, which are quite easy to use.

One first is to define mapper, @ SelectProvider to declare class ( CitySqlProvide ) and method name ( findByState ), 

public interface CityMapper {

    @SelectProvider(type = CitySqlProvide.class, method = "findByState")
    List<City> findByState(@Param("state") String state);
}

 2 When using String to construct query statements, it is difficult and error-prone. Therefore, MyBatis provides SQL public method construction methods , and does not need to write a complete String statement . Let's see how to use the public methods of org.apache.ibatis.jdbc.SQL.

import org.apache.ibatis.jdbc.SQL;
public class CitySqlProvide {
    public String findByState(String state) {
        return new SQL() {{
            this.SELECT("*").FROM("city").WHERE("state = #{state}");
        }}.toString();
    }
}