mysql 动态sql

@Data
public class Blog {
    private String id;
    private String title;
    private String author;
    private Date createTime;
    private int views;
}

public interface BlogMapper {

    int addBlog(Blog blog);

    List<Blog> queryBlogIf(Map map);

}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mapper.BlogMapper">

    <insert id="addBlog" parameterType="blog">
        insert into blog (id,title,author,create_time,views) values (#{id},#{title},#{author},#{createTime},#{views})
    </insert>

    <select id="queryBlogIf" parameterType="map" resultType="blog">
        select * from blog 
　　　　　　<where>
        　　<if test="title != null">
            　　and title=#{title}
        　　</if>
        　　<if test="author != null">
            　　and author=#{author}
        　　</if>
　　　　　　</where>
    </select>
</mapper>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <properties resource="db.properties"/>
    
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
    
    <typeAliases>
        <typeAlias type="com.example.entity.Blog" alias="blog"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <package name="com.example.mapper"/>
    </mappers>

</configuration>

public class IDUtil {
    public static String getId(){
        return UUID.randomUUID().toString().replace("-","");
    }
}