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一、PHP 基础部分
1》 获取文件名
function get_ext1($file_name){
return strrchr($file_name, '.');
}
function get_ext2($file_name){
return substr($file_name, strrpos($file_name, '.'));
}
function get_ext3($file_name){
return array_pop(explode('.', $file_name));
}
function get_ext4($file_name){
return pathinfo($file_name, PATHINFO_EXTENSION);
}
function get_ext5($file_name){
return strrev(substr(strrev($file_name), 0, strpos(strrev($file_name), '.')));
}echo get_ext1('/tp5/app/controller/d.class.php');
2》获取url 扩展名
3》字符串'open_door' 转换成'OpenDoor'、'make_by_id' 转换成 'MakeById'。
function str_explode($str){
$str_arr=explode('_',$str);
$str_implode=implode('',$str_arr);
$str_implode=implode('',explode('',ucwords($str_implode)));
return $str_implode;
}
$strexplode=str_explode('make_by_id');
print_r($strexplode);
方法二：
$str='make_by_id!';
$expStr=explode('_',$str);
for($i=0;$i<count($expStr);$i++)
{
echo ucwords($expStr[$i]);
}
方法三：
echo str_replace(' ','',ucwords(str_replace('_',' ','open_door')))4》unset()
$test = 'aaaaaa';
$abc = & $test;
unset($test);
echo $abc; aaaaaa
二、知识点部分
1》MySQL数据库中的字段类型varchar和char的主要区别是什么?那种字段的查找效率要高，为什么?
Varchar是变长，节省存储空间，char是固定长度。查找效率要char型快，因为varchar是非定长，必须先查找长度，然后进行数据的提取，比char定长类型多了一个步骤，所以效率低一些
三、排序部分
1》冒泡排序
function bubble_sort($array){
$count = count($array);
if ($count <= 0) return false;
for($i=0; $i<$count; $i++){
for($j=$i; $j<$count-1; $j++){
if ($array[$i] > $array[$j]){
$tmp = $array[$i];
$array[$i] = $array[$j];
$array[$j] = $tmp;
}
}
}
return $array;
}
2》快速排序
function quick_sort($array) {
if (count($array) <= 1) return $array;
$key = $array[0];
$left_arr = array();
$right_arr = array();
for ($i=1; $i<count($array); $i++){
if ($array[$i] <= $key)
$left_arr[] = $array[$i];
else
$right_arr[] = $array[$i];
}
$left_arr = quick_sort($left_arr);
$right_arr = quick_sort($right_arr);
return array_merge($left_arr, array($key), $right_arr);
}
3》二分查找排序
function A($arr, $target)
{
//定义开始和结束的下标
$start = 0;
$end = count($arr) - 1;
//循环
while($start <= $end)
{
//取中间值
$mid = floor(($start + $end) / 2);
if($arr[$mid] == $target)
{
return $mid;
}
//查询的数小，往左继续查找
if($arr[$mid] > $target)
{
$end = $mid - 1;
}
//查询的数大，往右继续查找
if($arr[$mid] < $target)
{
$start = $mid + 1;
}
}
}
echo A($arr, 11);
4》顺序查找排序
function seq_sch($array, $n, $k){
$array[$n] = $k;
for($i=0; $i<$n; $i++){
if($array[$i]==$k){
break;
}
}
if ($i<$n){
return $i;
}else{
return -1;
}
}5》二维数组排序
function array_sort($arr, $keys, $order=0) {
if (!is_array($arr)) {
return false;
}
$keysvalue = array();
foreach($arr as $key => $val) {
$keysvalue[$key] = $val[$keys];
}
if($order == 0){
asort($keysvalue);
}else {
arsort($keysvalue);
}
reset($keysvalue);
foreach($keysvalue as $key => $vals) {
$keysort[$key] = $key;
}
$new_array = array();
foreach($keysort as $key => $val) {
$new_array[$key] = $arr[$val];
}
return $new_array;
}四、sql 部分
1》查询每门课都大于80分的同学的姓名：
select distinct name from grade where name not in (select distinct name from grade where score<=80);
或：
select name from grade group by name having min(score)>80;
2》平均分
select name from (
select count(*) t, sum(score) num, name from grade group by name
) as a where a.num>80*t;
或；
select name, avg(score) as sc from grade group by name having avg(score)>80;
3》 该标题内容为转载：https://www.cnblogs.com/cheng88/p/10585715.html
MySQL45道面试题及答案
create database school;
use school;
#学生表
create table `Student`
(
`Sno` varchar(20) not null COMMENT '人名',
`Sname` varchar(20) not null COMMENT '姓名',
`Ssex` varchar(20) not null COMMENT '性别',
`Sbirthday` datetime COMMENT '出生日期',
`Class` varchar(20) COMMENT '班级'
);
#课程表
create table `Course`(
`Cno` varchar(20) not null COMMENT '课程号',
`Cname` varchar(20) not null COMMENT '课程名称',
`Tno` varchar(20) not null COMMENT '教工编号'
);
#成绩表
Create table `Score` (
`Sno` varchar(20) not null COMMENT '学号',
`Cno` varchar(20) not NULL comment '课程号',
`Degree` DECIMAL(4,1) null COMMENT '成绩'
);
#教师表
create table `Teacher` (
`Tno` varchar(20) not null COMMENT '教工编号',
`Tname` varchar(20) not null COMMENT '教工姓名',
`Tsex` varchar(20) not null COMMENT '教工性别',
`Tbirthday` datetime null COMMENT '教工出生日期',
`Prof` varchar(20) null COMMENT '职称',
`Depart` varchar(20) null COMMENT '教工所在部门'
);
insert into `Student` value
(108,'曾华','男','1977-09-01',95033),
(105,'匡明','男','1975-10-02',95031),
(107,'王丽','女','1976-01-23',95033),
(101,'李军','男','1976-02-20',95033),
(109,'王芳','女','1975-02-10',95031),
(103,'陆军','男','1974-06-03',95031);
insert into `Course` value
(3-105,'计算机导论',825),
(3-245,'操作系统',804),
(6-166,'数字电路',856),
(9-888,'高等数学',831);
insert into `Score` value
(103,3-245,86),
(105,3-245,75),
(109,3-245,68),
(103,3-105,92),
(105,3-105,88),
(109,3-105,76),
(101,2-105,64),
(107,3-105,91),
(108,3-105,78),
(101,6-166,85),
(107,6-166,79),
(108,6-166,81);
insert into `Teacher` value
(804,'李城','男','1958-12-02','副教授','计算机系'),
(856,'张旭','男','1969-03-12','讲师','电子工程系'),
(825,'王萍','女','1972-05-05','助教','计算机系'),
(831,'刘冰','女','1977-08-14','助教','电子工程系');
#1、 查询Student表中的所有记录的Sname、Ssex和Class列。
select `Sname`,`Ssex`,`Class` from `Student`;
#2、 查询教师所有的单位即不重复的Depart列。（多练）
select distinct Depart from `Teacher`;
-- 第三题 查询Student表的所有记录。
select * from `Student`;
-- 第四题 查询Score表中成绩在60到80之间的所有记录。
select * from `Score` where Degree >60 and Degree<80;
select * from `Score` where Degree between 60 and 80;
-- 第五题 查询Score表中成绩为85，86或88的记录。
select * from `Score` where Degree = 85 or Degree = 86 or Degree = 88;
select * from `Score` where Degree in(85,86,88);
-- 第六题 查询Student表中“95031”班或性别为“女”的同学记录。
select * from `Student` where Class = '95031' or Ssex ='女';
-- 第七题 以Class降序查询Student表的所有记录。
select * from `Student` order by Class desc;
-- 第八题 以Cno升序、Degree降序查询Score表的所有记录。
select * from `Score` order by Cno asc,Degree desc ;
-- 第九题 查询“95031”班的学生人数。
select count(*) from `Student` where Class = '95031';
-- 第十题 查询Score表中的最高分的学生学号和课程号。（子查询或者排序）
select Sno,Cno from `Score` where Degree=(select Max(Degree) from Score);
select Sno,Cno from `Score` order by Degree desc;
-- 第十一题 查询每门课的平均成绩。(group by:根据Cno进行分组)
select Cno,AVG(Degree) as 平均分 from `Score` group by Cno;
-- 第十二题 查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。
select * from `Score` where Cno like '3%' group by Cno having Count(Cno)>4;
-- 第十三题 查询分数大于70，小于90的Sno列。
select Sno from `Score` where Degree>70 or Degree<90;
select Sno from `Score` where Degree between 70 and 90;
-- 第十四题 查询所有学生的Sname、Cno和Degree列。
select Sname,Cno from `Student` join `Score` on `Student`.Sno = `Score`.Sno;
-- 第十五题 查询所有学生的Sno、Cname和Degree列。
select Sno,Cname,Degree from Score join Course on Course.Cno = Score.Cno;
-- 第十六题 查询所有学生的Sname、Cname和Degree列。
select Sname,Cname,Degree from `Student` join Score on
`Student`.Sno = `Score`.Sno join Course on `Course`.Cno = `Score`.Sno;
-- 第十七题 查询“95033”班学生的平均分。(子查询or条件查询)
select AVG(Degree) from `Score` where Sno in(select Sno from `Student` where Class='95033');
select Avg(Degree) from `Score`,Student where Student.Sno = Score.Sno and Class = '95033';
-- 第十八题 假设使用如下命令建立了一个grade表：
create table `grede`(
`low` int COMMENT '人名',
`upp` int not null COMMENT '课长',
`rank` varchar(20) not null COMMENT '等级'
);
insert into `grede` values(90,100,'A');
insert into `grede` values(80,89,'B');
insert into `grede` values(70,79,'C');
insert into `grede` values(60,69,'D');
insert into `grede` values(0,59,'E');
-- 现查询所有同学的Sno、Cno和rank列。(between选取两个值之间的数据范围)
select Sno,Cno,Degree,rank from grede join Score on Score.Degree between
low and upp;
select Sno,Cno,Degree,rank from Score,grede where Degree between
low and upp;
-- 第十九题 查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。
select * from Student,Score where Score.Cno = '3-105' and Student.Sno = Score.Sno
and Score.Degree>(select Degree from Score where Cno = '3-105' and Sno = '109');
-- 第二十题 查询score中选学多门课程的同学中分数为非最高分成绩的记录。
select * from Score a where Degree<(select MAX(Degree)from Score b
where a.Cno = b.Cno) and Sno in(select Sno from Score group by Sno having count(*) > 1);
-- 第二十一题 查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。
select * from Student,Score where Student.Sno = Score.Sno and Score.Degree>
(select Degree from Score where Cno='3-105' and Sno = '109');
-- 第二十二题 查询和学号为107的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
select Sno,Sname,Sbirthday from student where year(Student.Sbirthday) = (
select year(Sbirthday) from student where Sno = '107'
);
-- 第二十三题 查询“张旭“教师任课的学生成绩
select Sno,Cno,Degree from Score where Cno in(select Cno from Course where
Tno in(select Tno from Teacher where Tname = '张旭'));
-- 第二十四题 查询选修某课程的同学人数多于5人的教师姓名。
select Tname from Teacher where Tno in(select Tno from Course where Cno in(select Cno from Score
group by Cno having Count(*)>5));
-- 第二十五题 查询95033班和95031班全体学生的记录。
select * from Student where Class = '95033' or Class = '95031';
-- 第二十六题 查询存在有85分以上成绩的课程Cno.
select distinct cno from Score where Degree>85;
-- 第二十七题 查询出“计算机系“教师所教课程的成绩表。
select Sno,Cno,Degree from Score where Cno in(select Cno from Course where Tno in(
select tno from Teacher where Depart = '计算机系'
));
-- 第二十八题查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。使用相关子查询
select Tname,Prof from Teacher a where Prof not in(select Prof from Teacher b where
a.Depart!=b.Depart);
-- 第二十九题 查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”课程的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。
select Cno,Sno,Degree from Score a where (select Degree from Score b where Cno='3-105' and
b.Sno = a.Sno)>=(select Degree from Score c where Cno='3-245' and c.Sno = a.Sno)order by
Degree desc ;
-- 第三十题 查询选修编号为“3-105”课程且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree.
select Cno,Sno,Degree from Score a where (select Degree from Score b where Cno='3-105' and
b.Sno=a.Sno)>(select Degree from Score c where Cno='3-245' and c.Sno=a.Sno);
-- 第三十一题 查询所有教师和同学的name、sex和birthday.
select distinct Sname as name,Ssex as sex,Sbirthday as birthday from student
union
select distinct Tname as name,Tsex as sex,Tbirthday as birthday from Teacher;
-- 第三十二题 查询所有“女”教师和“女”同学的name、sex和birthday.
select distinct Sname as name,Ssex as sex,Sbirthday as birthday from student where Ssex = '女'
union
select distinct Tname as name,Tsex as sex,Tbirthday as birthday from Teacher where Tsex = '女';
-- 第三十三题 查询成绩比该课程平均成绩低的同学的成绩表。
select Sno,Cno,Degree from Score a where a.Degree<(select AVG(Degree) from Score b where a.Cno = b.Cno);
-- 第三十四题 查询所有任课教师的Tname和Depart.
select Tname,Depart from Teacher where Tname in(select distinct Tname from Teacher,
Course,Score where Teacher.Tno = Course.Tno and Course.Cno = Score.Cno);
select Tname,Depart from Teacher where tno in (select tno from course where Cno in (select distinct Cno from Score));
-- 第三十五题 查询所有未讲课的教师的Tname和Depart.
select Tname,Depart from Teacher where Tname not in(select distinct Tname from Teacher,Course,Score where Teacher.Tno=Course.Tno and Course.Cno = Score.Cno);
-- 第三十六题 查询至少有2名男生的班号。
select Class from student where Ssex='男' group by Class having count(*)>1;
-- 第三十七题 查询Student表中不姓“王”的同学记录。
select * from Student where Sname not like ('王%');
-- 第三十八题 查询Student表中每个学生的姓名和年龄。
select Sname,YEAR(GETDATE())-year(Sbirthday) from student;
-- 第三十九题 查询Student表中最大和最小的Sbirthday日期值
select MAX(Sbirthday) as 最大,MIN(Sbirthday) as 最小 from student;
-- 第四十题 以班号和年龄从大到小的顺序查询Student表中的全部记录
select * from Student order by Class desc ,Sbirthday asc;
-- 第四十一题 查询“男”教师及其所上的课程。
select Tname,Cname from Teacher,Course where Tsex='男' and Teacher.Tno = Course.Tno;
-- 第四十二题 查询最高分同学的Sno、Cno和Degree列。
select Sno,Cno,Degree from Score where Degree=(select MAX(Degree) FROM score);
-- 第四十三题 查询和“李军”同性别的所有同学的Sname.
select SName from Student where Ssex=(select Ssex from Student where Sname='李军')and Sname
not in ('李军');
-- 第四十四题 查询和“李军”同性别并同班的同学Sname
select Sname from Student where Ssex=(select Ssex from Student where Sname='李军')and Sname not in
('李军')and Class=(select Class from Student where Sname='李军');
-- 第四十五题 查询所有选修“计算机导论”课程的“男”同学的成绩表
select Sno,Degree from Score where Sno in(select Sno from Student where Ssex='男')and Cno in
(select Cno from Course where Cname='计算机导论');
五、linux 部分
六、逻辑题（图）
PHP实现螺旋矩阵(螺旋数组）
转载：https://www.cnblogs.com/chenqionghe/p/4765802.html
function rotationSort($row=5,$col=5)
{
$k=1;
$result = array();
$small = $col < $row ? $col : $row;
$count = ceil($small / 2);
for($i=0; $i<$count; $i++)
{
$maxRight = $col-1-$i;//右边最大坐标
$maxBottom = $row -1 -$i;//下面最大坐标
for($j=$i; $j<=$maxRight; $j++) //构造上边一条线 纵坐标最小,横坐标递增
{
$result[$i][$j] = $k++;
}
for($j=$i; $j<$maxBottom; $j++) //构造右边一条线 纵坐标递增,横坐标最大
{
$result[$j+1][$maxRight] = $k++;
}
for($j=$maxRight-1;$j>=$i; $j--) //构造下边一条线 纵坐标最大,横坐标递减
{
if($result[$maxBottom][$j]) break;
$result[$maxBottom][$j] = $k++;
}
for($j=$maxBottom-1;$j>$i;$j--) //构造左边一条线 纵坐标递减,横坐标最小
{
if($result[$j][$i]) break;
$result[$j][$i] = $k++;
}
}
return $result;
}
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$row = 5;
$col = 5;
$arr = rotationSort($row,$col);
printArray($arr,$row,$col);
2，
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