图书管理系统，求大神解释每句含义

Question

MYSQL_RES * recordSet = mysql_store_result(conn); 
    long j = mysql_num_fields(recordSet);
    MYSQL_ROW row;
    char *dd,*ee;
    int i=0;
    data=new char[10];
    strcpy(data,"");
    while( row = mysql_fetch_row(recordSet)) 
    { 
        dd=new char[200];
        strcpy(dd,"");
        for(int l=0 ; l< j;l++) 
        { 
            if(row[l]==NULL || !strlen(row[l])){}
            else 
            {
                strcat(dd,row[l]);  
                strcat(dd,"|");
            }
        } 
        i=strlen(data)+1;
        ee=data;
        data=NULL;
        data=new char[strlen(dd)+i+1];
        strcpy(data,ee);
        strcat(data,dd);
        strcat(data,"@");
        delete dd;
        delete ee;
    }
}

Answer 1

 MYSQL_RES * recordSet = mysql_store_result(conn);  //得到一个结果集（recordset）
    long j = mysql_num_fields(recordSet); 
    MYSQL_ROW row; //代表一行
    char *dd,*ee;
    int i=0;
    data=new char[10];
    strcpy(data,"");
    while( row = mysql_fetch_row(recordSet))  //这是遍历表，mysql_fetch_row(recordSet)如果返回false说明遍历结束
    { 
        dd=new char[200];
        strcpy(dd,"");
        for(int l=0 ; l< j;l++)  //row[i]代表这一行中的某一列
        { 
            if(row[l]==NULL || !strlen(row[l])){}
            else 
            {
                strcat(dd,row[l]);  
                strcat(dd,"|");
            }
        } 
        i=strlen(data)+1;
        ee=data;
        data=NULL;
        data=new char[strlen(dd)+i+1];
        strcpy(data,ee);
        strcat(data,dd);
        strcat(data,"@");
        delete dd;
        delete ee;
    }
}