in cloumn subquery

data/2.MySQL中阶/6.子查询/6. NOT IN/config.json

-{
-  "node_id": "mysql-06525286a9d4488d94e85b6bd36e3c1e",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [
-    ["mysql", "not in"]
-  ],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/2.MySQL中阶/6.子查询/7. 列子查询/config.json → data/2.MySQL中阶/6.子查询/6. 列子查询/config.json

 {
   "node_id": "mysql-7bc092b1b1854dd3b88eed3a517b96a2",
-  "keywords": ["子查询", "列子查询"],
+  "keywords": [
+    "子查询",
+    "列子查询"
+  ],
   "children": [],
-  "export": [],
+  "export": [
+    "in_column.json"
+  ],
   "keywords_must": [
-    ["mysql", "列子查询"]
+    [
+      "mysql",
+      "列子查询"
+    ]
   ],
   "keywords_forbid": [],
   "group": 0

data/2.MySQL中阶/6.子查询/6. 列子查询/in_clumn.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "in_column.md",
+  "notebook_enable": false,
+  "exercise_id": "2ded48602e384fc2b5476186e8b91842"
+}
\ No newline at end of file

data/2.MySQL中阶/6.子查询/6. 列子查询/in_column.json

+{
+  "type": "code_options",
+  "author": null,
+  "source": "in_column.md",
+  "notebook_enable": false,
+  "exercise_id": "464fd8f686284280afbee9424ed4ae65"
+}
\ No newline at end of file

data/2.MySQL中阶/6.子查询/6. 列子查询/in_column.md

+# 列子查询
+
+Joe 打算写一个查询，根据员工表
+
+```mysql
+create table employee(
+    id int primary key auto_increment,
+    dept varchar(256),
+    name varchar(256),
+    post varchar(16)
+)
+```
+
+统计每个部门的人数，但是他不打算用 group by。那么还可以怎做？
+
+## 答案
+
+```mysql
+select distinct(dept) as dept, 
+               (select count(*) from employee as i where i.dept=o.dept) as emp  
+from employee as o
+```
\ No newline at end of file

data/tree.json

@@ -1240,21 +1240,6 @@
                       "group": 0
                     }
                   },
-                  {
-                    " NOT IN": {
-                      "node_id": "mysql-06525286a9d4488d94e85b6bd36e3c1e",
-                      "keywords": [],
-                      "children": [],
-                      "keywords_must": [
-                        [
-                          "mysql",
-                          "not in"
-                        ]
-                      ],
-                      "keywords_forbid": [],
-                      "group": 0
-                    }
-                  },
                   {
                     " 列子查询": {
                       "node_id": "mysql-7bc092b1b1854dd3b88eed3a517b96a2",