diff --git a/liu.js b/liu.js
new file mode 100644
index 0000000000000000000000000000000000000000..b45b2de7f79326180a009b9ba5b31e5d5724a056
--- /dev/null
+++ b/liu.js
@@ -0,0 +1,49 @@
+var mysql      = require('mysql');
+var connection = mysql.createConnection({
+  host     : '127.0.0.1',
+  user     : 'root',
+  password : 'root',
+  database : 'student'
+});
+connection.connect();
+let page=1;
+let pageSize=2;
+console.log(new Date().toLocaleString().replace("/","-").replace("/","-"));
+let sql = "select * from student limit " + (page - 1) * pageSize + "," + pageSize;
+connection.query(sql, (err, data) => {
+ 
+  console.log(data);
+ 
+});
+connection.query('SELECT count(*) from student', function (error, results, fields) {
+  if (error) throw error;
+  console.log("查询结果学生总数是");
+  console.log(results);
+});
+connection.query('select count(*) from student where stu_six="男"',function (error, results) {
+  if (error) throw error;
+  console.log("查询结果是男的");
+  console.log(results);
+});
+connection.query('select count(*) from student where stu_six="女"',function (error, results) {
+  if (error) throw error;
+  console.log("查询结果是女的");
+  console.log(results);
+});
+connection.query('select count(*) from student where stu_age<18',function (error, results) {
+  if (error) throw error;
+  console.log("查询结果小于18是");
+  console.log(results);
+});
+connection.query('select count(*) from student where stu_age>=18 and stu_age<45',function (error, results) {
+  if (error) throw error;
+  console.log("查询结果大于等于18，小于45是");
+  console.log(results);
+});
+connection.query('select count(*) from student where stu_age<45',function (error, results) {
+  if (error) throw error;
+  console.log("查询结果大于45是");
+  console.log(results);
+});
+
+connection.end();
\ No newline at end of file
diff --git a/liu/open.js b/liu/open.js
new file mode 100644
index 0000000000000000000000000000000000000000..e238b130c2f36388a706bdd1df288b693995f5fb
--- /dev/null
+++ b/liu/open.js
@@ -0,0 +1,49 @@
+// ## 作业1:使用open write close的形式去创建一个大文件,
+// 内容随机写点数据,计算出这个大文件出现最多的字符.
+var fs=require('fs');
+fs.open("open.txt",'w',function(err,fd) {
+    // length || (length=8);
+    //const buf1 = Buffer.alloc(5000);
+    const letters='qwertyuiopasdfghjklzxcvbnm';
+    let total='';
+        total+=letters;
+    let result=''
+    let length=1000;
+    while(length>990){
+       length--
+       result+=total[Math.floor(Math.random()*total.length)];
+       fs.writeSync(fd,result+'');
+       
+    }
+    fs.close(fd)
+})
+var fs = require('fs');
+
+// 打开一个流:
+var rs = fs.createReadStream('open.txt', 'utf-8');
+
+rs.on('data', function (chunk) {
+    console.log(chunk);
+    let str=chunk;
+    let k={}
+    for (let i = 0; i < str.length; i++) {
+       let chars=str.charAt(i);
+       if (k[chars]) {
+        k[chars]++;
+       }else{
+        k[chars]=1;
+       }
+        
+    }
+    console.log(k);
+    let max=0;
+    let letter=''
+    for(let i in k){
+     if(k[i]>max){
+         max=k[i];
+         letter=i;
+        
+     }
+    }
+    console.log(`./open.txt中出现最多的文字是${letter},出现了${max}次`);
+});
diff --git a/liu/open.txt b/liu/open.txt
new file mode 100644
index 0000000000000000000000000000000000000000..ed79a11147be97f5e10f563bfa35caefd687381d
--- /dev/null
+++ b/liu/open.txt
@@ -0,0 +1 @@
+iiyiyziyzriyzraiyzrapiyzrapxiyzrapxqiyzrapxqliyzrapxqlk
\ No newline at end of file
diff --git "a/\345\210\230\351\270\277\345\245\207/aaa.js" "b/\345\210\230\351\270\277\345\245\207/aaa.js"
new file mode 100644
index 0000000000000000000000000000000000000000..052d990d4605b4a070d35390409ddff0f8f8869f
--- /dev/null
+++ "b/\345\210\230\351\270\277\345\245\207/aaa.js"
@@ -0,0 +1,24 @@
+'use strict';
+var fs =require('fs');
+function a(){
+    for (let i = 1; i <= 100; i++) {
+        fs.writeFileSync(i+".txt",Math.ceil(Math.random()*1000+1)+"")*Math.ceil(Math.random()*100+1)
+       
+    }
+}
+
+
+a(fs);
+var num=null
+function b(){
+    
+     for (let i = 1; i <= 100; i++) {
+        var j=fs.readFileSync(i+".txt");
+        num=Number(j)>num?Number(j):num;
+       
+        
+     }
+        console.log(num); 
+ 
+}
+b()
diff --git "a/\346\261\244\344\272\246\345\207\241node\344\275\234\344\270\232/\346\250\241\345\235\227\344\275\234\344\270\232/\345\212\240\345\207\217\344\271\230\351\231\244.js" "b/\346\261\244\344\272\246\345\207\241node\344\275\234\344\270\232/\346\250\241\345\235\227\344\275\234\344\270\232/\345\212\240\345\207\217\344\271\230\351\231\244.js"
deleted file mode 100644
index ba307a85f7bf85fb5d5f58f0d7ce81fdf70bb59e..0000000000000000000000000000000000000000
--- "a/\346\261\244\344\272\246\345\207\241node\344\275\234\344\270\232/\346\250\241\345\235\227\344\275\234\344\270\232/\345\212\240\345\207\217\344\271\230\351\231\244.js"
+++ /dev/null
@@ -1,16 +0,0 @@
-//作业：写个加减乘除的模块（尽量少写暴露,要考虑复用性），供外部使用. 作业每个分支要建一个目录（自己名字）
-let obj={
-    'add':function(num1,num2){
-        return num1+num2;
-    },
-    'sub':function(num1,num2){
-        return num1-num2;
-    },
-    'mul':function(num1,num2){
-        return num1*num2;
-    },
-    'divide':function(num1,num2){
-        return num1/num2;
-    }
-};
-module.exports=obj;
\ No newline at end of file
diff --git "a/\346\261\244\344\272\246\345\207\241node\344\275\234\344\270\232/\346\250\241\345\235\227\344\275\234\344\270\232/\350\277\220\350\241\214.js" "b/\346\261\244\344\272\246\345\207\241node\344\275\234\344\270\232/\346\250\241\345\235\227\344\275\234\344\270\232/\350\277\220\350\241\214.js"
deleted file mode 100644
index 618e6f240c9b18b16065ebfcb343fa88b10787b3..0000000000000000000000000000000000000000
--- "a/\346\261\244\344\272\246\345\207\241node\344\275\234\344\270\232/\346\250\241\345\235\227\344\275\234\344\270\232/\350\277\220\350\241\214.js"
+++ /dev/null
@@ -1,8 +0,0 @@
-let objs=require("./加减乘除");
-// console.log(objs);
-console.log(objs.add(1,2));
-console.log(objs.sub(81,23));
-console.log(objs.mul(6,2));
-console.log(objs.divide(18,3));
-
-