functions for date and time

data/2.MySQL中阶/10.用户和权限/1.创建普通用户/create_user.json

@@ -3,5 +3,5 @@
   "author": "ccat",
   "source": "create_user.md",
   "notebook_enable": false,
-  "exercise_id": "b64ebf99bff14f69b2ef92049bb7b57c"
+  "exercise_id": "70eadd97073640d5ac486898c7294d34"
 }
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/config.json

+{
+  "node_id": "mysql-a7006c27131d4b87817a59717db7021c",
+  "keywords": [],
+  "children": [],
+  "export": [
+    "day.json",
+    "curtime.json",
+    "weekofyear.json",
+    "weekday.json",
+    "to_days.json",
+    "now.json"
+  ],
+  "keywords_must": [],
+  "keywords_forbid": [],
+  "group": 1
+}
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/curtime.json

+{
+  "type": "code_options",
+  "author": null,
+  "source": "curtime.md",
+  "notebook_enable": false,
+  "exercise_id": "bc88844a66244492947e98da40709619"
+}
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/curtime.md

+# 当前时间
+
+Joe 需要在程序中获取当前时间，但是不包含日期部分。下列哪些函数可以提供这个功能？
+
+1. now()
+2. curtime()
+3. sysdate()
+4. current_time()
+5. current_timestamp()
+
+## 答案
+
+```
+2, 4
+```
+
+## 选项
+
+### A
+
+```
+1, 2, 3, 4
+```
+
+### B
+
+全都可以
+
+### C
+
+全部都错
+
+### D
+
+```
+4, 5
+```
+
+### E
+
+```
+1, 2
+```

data/2.MySQL中阶/3.内置函数/5.时间日期函数/day.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "day.md",
+  "notebook_enable": false,
+  "exercise_id": "b64ebf99bff14f69b2ef92049bb7b57c"
+}
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/day.md

+# DAY
+
+Joe 需要从日期中提取当天是几号，下列哪些函数可以实现这个功能？
+
+1. DAY
+2. DAYOFMONTH
+3. DAYOFYEAR
+4. TO_DAYS
+
+## 答案
+
+1 和 2
+
+## 选项
+
+### A
+
+只有 1
+
+### B
+
+只有 2
+
+### C
+
+都不对
+ 
+### D
+
+全都可以
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/now.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "now.md",
+  "notebook_enable": false,
+  "exercise_id": "f628db00fb904159a301551adc981d78"
+}
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/now.md

+# 当前时间
+
+Joe 在程序中获取当前时间，下面哪个函数*不*能满足要求？
+
+1. now()
+2. sysdate()
+3. CURRENT_TIMESTAMP()
+4. LOCALTIME()
+5. current()
+
+## 答案
+
+5
+
+## 选项
+
+### A
+
+1
+
+### B
+
+2
+
+### C
+
+3
+
+### D
+
+4

data/2.MySQL中阶/3.内置函数/5.时间日期函数/to_days.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "to_days.md",
+  "notebook_enable": false,
+  "exercise_id": "c48b730d0d0f4347969e1c9375efd3c1"
+}
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/to_days.md

+# TO_DAYS
+
+TO_DAYS 函数返回的是？
+
+## 答案
+
+给定时间到 0000 年 1 月 1 日的天数。
+
+## 选项
+
+### A
+
+给定时间到 1970 年 1 月 1 日的天数。
+
+### B
+
+都不对
+
+### C
+
+当前时间到 0000 年 1 月 1 日的天数。
+
+### D
+
+当前时间到 1970 年 1 月 1 日的天数。

data/2.MySQL中阶/3.内置函数/5.时间日期函数/weekday.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "weekday.md",
+  "notebook_enable": false,
+  "exercise_id": "92dc6edd3bbb43969147763a3298bbea"
+}
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/weekday.md

+# WeekDay
+
+Joe 想要用 weekday 生成每周分析报表，这个函数会将如期映射为整数，当 weekday 返回 0 ，代表周几？
+
+## 答案
+
+周一
+
+## 选项
+
+### A
+
+周日
+
+### B
+
+周六
+
+### C
+
+全都不是
+
+### D
+
+视时区不同而变
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/weekofyear.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "now.md",
+  "notebook_enable": false,
+  "exercise_id": "5ef9bfa0d9b34219941e4b833fa54e77"
+}
\ No newline at end of file

data/2.MySQL中阶/3.内置函数/5.时间日期函数/weekofyear.md

+# WEEK OF YEAR
+
+下列函数中，哪些可以获取给定时间在一年中的第几周？
+
+1. week
+2. weekofyear
+3. weekday
+4. dayofyear
+5. dayofweek
+
+## 答案
+
+```
+1, 2
+```
+
+## 选项
+
+### A
+
+```
+1, 2, 3, 4
+```
+
+### B
+
+全部都是
+
+### C
+
+全都不是
+
+### D
+
+```
+1, 2, 3, 5
+```
\ No newline at end of file

data/2.MySQL中阶/9.备份与恢复/1.数据导入和导出/dump.json

 {
   "type": "code_options",
-  "author": null,
+  "author": "Mars",
   "source": "dump.md",
   "notebook_enable": false,
   "exercise_id": "d581e2fe632b4737b6da553bd6455ed7"

data/tree.json

@@ -836,7 +836,7 @@
               }
             },
             {
-              "系统函数": {
+              "内置函数": {
                 "node_id": "mysql-f436539236694bb9a4014de11e06ad82",
                 "keywords": [],
                 "children": [
@@ -889,6 +889,16 @@
                       "group": 0
                     }
                   },
+                  {
+                    "时间日期函数": {
+                      "node_id": "mysql-a7006c27131d4b87817a59717db7021c",
+                      "keywords": [],
+                      "children": [],
+                      "keywords_must": [],
+                      "keywords_forbid": [],
+                      "group": 1
+                    }
+                  },
                   {
                     "其它函数": {
                       "node_id": "mysql-f2fe15b77d5d4ecb92e2840e8b831af2",