datetime

data/1.MySQL初阶/4.数据类型/1.数值类型/config.json

@@ -3,7 +3,7 @@
   "keywords": [],
   "children": [],
   "export": [
-    "number.json"
+    "numbers.json"
   ],
   "keywords_must": [],
   "keywords_forbid": [],

data/1.MySQL初阶/4.数据类型/1.数值类型/number.json → data/1.MySQL初阶/4.数据类型/1.数值类型/numbers.json

 {
   "type": "code_options",
-  "author": "ccat",
-  "source": "number.md",
+  "author": "Mars",
+  "source": "numbers.md",
   "notebook_enable": false,
-  "exercise_id": "39244600680e40848e6ab8af71f22cf1"
+  "exercise_id": "0093549d885b4eec8f556fc86cc60431"
 }
\ No newline at end of file

data/1.MySQL初阶/4.数据类型/2.日期和时间类型/config.json

@@ -2,7 +2,9 @@
   "node_id": "mysql-7256fe88bcf241d486c9e2e254ef66d9",
   "keywords": [],
   "children": [],
-  "export": [],
+  "export": [
+    "datetime.json"
+  ],
   "keywords_must": [],
   "keywords_forbid": [],
   "group": 0

data/1.MySQL初阶/4.数据类型/2.日期和时间类型/datetime.json

+{
+  "type": "code_options",
+  "author": "Mars",
+  "source": "datetime.md",
+  "notebook_enable": false,
+  "exercise_id": "9f51c5816b1047368bdab70cb20d5116"
+}
\ No newline at end of file

data/1.MySQL初阶/4.数据类型/2.日期和时间类型/datetime.md

+# 时间默认值
+
+Joe 写了一个订单表的创建语句：
+
+```mysql
+create table orders (
+    id int primary key auto_increment,
+    item_id int,
+    amount int,
+    unit_price decimal(12, 4),
+    total_price decimal(12, 4)
+);
+```
+
+现在，Joe 需要给这个表加入下单时间，即订单写入数据库的时间，那么他应该将这个语句修改为：
+
+## 答案
+
+```mysql
+create table orders (
+    id int primary key auto_increment,
+    item_id int,
+    amount int,
+    unit_price decimal(12, 4),
+    total_price decimal(12, 4),
+    ts timestamp default now()
+);
+```
+
+## 选项
+
+### A
+
+```mysql
+create table orders (
+    id int primary key auto_increment,
+    item_id int,
+    amount int,
+    unit_price decimal(12, 4),
+    total_price decimal(12, 4),
+    ts varchar(16) default now()
+);
+```
+
+### B
+
+```mysql
+create table orders (
+    id int primary key auto_increment,
+    item_id int,
+    amount int,
+    unit_price decimal(12, 4),
+    total_price decimal(12, 4),
+    ts varchar(16) format 'yyyy-mm-dd'
+);
+```
+
+### C
+
+```mysql
+create table orders (
+    id int primary key auto_increment,
+    item_id int,
+    amount int,
+    unit_price decimal(12, 4),
+    total_price decimal(12, 4),
+    ts date default now()
+);
+```
+
+### D
+
+```mysql
+create table orders (
+    id int primary key auto_increment,
+    item_id int,
+    amount int,
+    unit_price decimal(12, 4),
+    total_price decimal(12, 4),
+    ts datetime default now()
+);
+```