fly on exercises

data/1.PostgreSQL初阶/3.查询数据/1.psql/config.json

+{
+  "node_id": "pg-ee5c6d4a073b45a7995ba351ab9de46e",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/2.SQL基本语法/basic.json

+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "basic.md",
+  "notebook_enable": false,
+  "exercise_id": "76fffa1781f140fd9abee9231a7186f4"
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/2.SQL基本语法/basic.md

+# 基本语法
+
+下列 SQL 语句，哪一项不合法？
+
+## 答案
+
+```postgresql
+from test select abc;
+```
+
+## 选项
+
+
+### A
+
+```postgresql
+select 3.14;
+```
+
+### B
+
+```postgresql
+select * from employee;
+```
+
+### C
+
+```postgresql
+select * from employee where dept = 'hr';
+```
+
+### D
+
+```postgresql
+select id, name, dept, salary from employee where salary > 10000::money;
+```
+
+### E
+
+```postgresql
+select now();
+```
+

data/1.PostgreSQL初阶/3.查询数据/2.SQL基本语法/config.json

+{
+  "node_id": "pg-dca8da7637f94ded91a1871daa51746e",
+  "keywords": ["语法", "select"],
+  "children": [],
+  "export": ["basic.json"]
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/concept.json

+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "concept.md",
+  "notebook_enable": false,
+  "exercise_id": "88b033cd97c642ef9900e5e091e335ff"
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/concept.md

+# 基本概念
+
+下列叙述中，正确的是
+
+1. 带有 select 关键字的查询不会修改数据
+2. 查询表需要 select 权限
+3. 修改一个数据库表或对象的结构，通常语句中会出现 create、add、drop、alter 等关键字
+4. 修改数据内容，通常会出现update、insert、delete等关键字
+5. update、insert、delete可以单独授权
+
+## 答案
+
+2, 3, 4, 5
+
+## 选项
+
+### A
+
+1, 2, 3, 4, 5
+
+### B
+
+4, 5
+
+### C
+
+1, 2, 3
+
+### D
+
+3, 4, 5
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/config.json

+{
+  "node_id": "pg-b0f366abe12e41b0a9672d317e556662",
+  "keywords": ["DML", "insert", "update", "delete"],
+  "children": [],
+  "export": [
+    "insert.json",
+    "update.json",
+    "delete.json",
+    "concept.json"
+  ]
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/delete.json

+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "delete.md",
+  "notebook_enable": false,
+  "exercise_id": "78e6ca15ba794ef3b2092de4640308b9"
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/delete.md

+# 删除
+
+SmartMarket 公司的业务数据库中，有一个 orders 表，其结构主要是以下形态：
+
+```postgresql
+create table orders
+(
+    id         serial primary key,
+    meta       jsonb     default '{}'::jsonb,
+    content    jsonb     default '{}'::jsonb,
+    created_at timestamp default now(),
+    deal       boolean
+)
+```
+
+有一个业务系统会实时的将已经成交（deal 字段为 true）的订单数据转储，现在我们仅需要一个清理 程序，将已经成 交的数据从 orders 表删除并记录被删除的数据id。下面哪个操作是对的？
+
+## 答案
+
+在一个独立的定时任务中执行
+
+```postgresql
+delete
+from orders
+where deal
+returning id;
+```
+
+并记录id
+
+## 选项
+
+### A
+
+在一个独立的定时任务中执行
+
+```postgresql
+truncate orders;
+```
+
+### B
+
+在一个独立的定时任务中执行
+
+```postgresql
+delete
+from orders;
+```
+
+### C
+
+在一个独立的定时任务中执行
+
+```postgresql
+drop table orders;
+create table orders
+(
+    id         serial primary key,
+    meta       jsonb     default '{}'::jsonb,
+    content    jsonb     default '{}'::jsonb,
+    created_at timestamp default now(),
+    deal       boolean
+);
+```
+
+### D
+
+建立视图
+
+```postgresql
+create view order_view as
+select id, meta, content, created_at
+from orders
+where not deal;
+```
+
+并要求业务系统只能访问这个视图。
+
+### E
+
+在一个独立的定时任务中执行
+
+```postgresql
+delete
+from orders
+where deal;
+```
+
+并记录操作前后表中的最大 id
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/insert.json

+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "insert.md",
+  "notebook_enable": false,
+  "exercise_id": "2d562e3ae4a84e648de31452a67ba71f"
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/insert.md

+# 插入
+
+现有一个表：
+
+```postgresql
+create table book(
+    id serial primary key ,
+    title text not null ,
+    meta jsonb default '{}'::jsonb,
+    price money,
+    isbn text not null ,
+    publish_at date not null 
+);
+create unique index on book(isbn);
+create index on book using gin(meta);
+```
+
+那么下列哪个选项的代码可以执行成功？
+
+## 答案
+
+```postgresql
+insert into book(title, price, isbn, publish_at) select 'a book title', 25.4, 'xx-xxxx-xxxx', '2019-12-1'::date;
+insert into book(title, price, isbn, publish_at) select 'a other book title', 25.4, 'yy-yyyy-xxxx', '2019-12-1'::date; 
+```
+
+## 选项
+
+### 唯一键冲突
+
+```postgresql
+insert into book(title, price, isbn, publish_at) select 'a book title', 25.4, 'xx-xxxx-xxxx', '2019-12-1'::date;
+insert into book(title, price, isbn, publish_at) select 'a other book title', 35.4, 'xx-xxxx-xxxx', '2019-12-1'::date; 
+```
+
+### 缺少必要的列
+
+```postgresql
+insert into book(price, isbn, publish_at) select 25.4, 'xx-xxxx-xxxx', '2019-12-1'::date;
+insert into book(price, isbn, publish_at) select 35.4, 'yy-yyyy-xxxx', '2019-12-1'::date;
+```
+
+### 类型错误
+
+```postgresql
+insert into book(title, price, isbn, publish_at) select 'a book title', 'unknown', 'xx-xxxx-xxxx', '2019-12-1'::date;
+insert into book(title, price, isbn, publish_at) select 'a other book title', 'unknown', 'xx-xxxx-xxxx', '2019-12-1'::date;
+```
+
+### 违反非空约束
+
+```postgresql
+insert into book(title, price, isbn, publish_at) select null, 'unknown', 'xx-xxxx-xxxx', '2019-12-1'::date;
+insert into book(title, price, isbn, publish_at) select null, 'unknown', 'xx-xxxx-xxxx', '2019-12-1'::date;
+```

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/update.json

+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "update.md",
+  "notebook_enable": false,
+  "exercise_id": "d6f2c270c3cd41a499715e55a2c565ba"
+}
\ No newline at end of file

data/1.PostgreSQL初阶/3.查询数据/3.SQL、DML和DDL/update.md

+# 更新数据
+
+现有 employee 表如下：
+
+```postgresql
+create table employee
+(
+    id serial primary key,
+    name text,
+    dept text,
+    salary money
+);
+```
+
+我们希望修改销售部(dept 字段为 sale)员工 Dora Muk 的工资，将其增加 1000，返回她的工号。正确的修改语句是：
+
+## 答案
+
+```postgresql
+update employee set salary = salary + 1000 where dept = 'sale' and name = 'Dora Muk' returning id;
+```
+
+## 选项
+
+### 过滤条件不严谨
+
+```postgresql
+update employee set salary = salary + 1000 where name = 'Dora Muk' returning id;
+```
+
+### 没有返回员工id
+
+```postgresql
+update employee set salary = salary + 1000 where dept = 'sale' and name = 'Dora Muk';
+```
+
+
+### 缺少过滤条件
+
+```postgresql
+update employee set salary = salary + 1000 returning id;
+```
+
+### 错误的赋值语句
+
+```postgresql
+update employee set salary += 1000 returning id;
+```
+

data/2.PostgreSQL中阶/2.服务端编程/6.过程化编程/config.json

+{
+  "node_id": "pg-eb4048b7dfd3469f8049330ba78427b5",
+  "keywords": [],
+  "children": [],
+  "export": ["loop.json"]
+}
\ No newline at end of file

data/2.PostgreSQL中阶/2.服务端编程/6.过程化编程/loop.json

+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "loop.md",
+  "notebook_enable": false,
+  "exercise_id": "8d25c0639365404ba3c61282e5ea32ba"
+}
\ No newline at end of file

data/2.PostgreSQL中阶/2.服务端编程/6.过程化编程/loop.md

+# 循环
+
+下面哪一项定义的函数可以生成指定范围内的整数数列？
+
+## 答案
+
+```postgresql
+create function gen(start integer, stop integer) returns setof integer as $$
+begin 
+    for idx in start .. stop loop
+        return next idx;
+    end loop;
+end;
+$$ language plpgsql;
+```
+
+## 选项
+
+### A
+
+```postgresql
+create function gen(start integer, stop integer) returns integer as $$
+begin 
+    for idx in start .. stop loop
+        return idx;
+    end loop;
+end;
+$$ language plpgsql;
+```
+
+### B
+
+```postgresql
+create function gen(start integer, stop integer) returns integer as $$
+begin 
+    for idx in start .. stop loop
+        yield idx;
+    end loop;
+end;
+$$ language plpgsql;
+```
+
+### C
+
+```postgresql
+create function gen(start integer, stop integer) returns setof integer as $$
+begin 
+    for idx in start .. stop loop
+        return idx;
+        idx += 1;
+    end loop;
+end;
+$$ language plpgsql;
+```
+
+### D
+
+```postgresql
+create function gen(start integer, stop integer) returns setof integer as $$
+begin 
+    for idx in start .. stop loop
+        select idx;
+    end loop ;
+end;
+$$ language plpgsql;
+```
\ No newline at end of file

data/2.PostgreSQL中阶/2.服务端编程/7.DDL/config.json

+{
+  "node_id": "pg-0378bcd60ccd4dfebcfead92abbdd673",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file

data/3.PostgreSQL高阶/2.高级数据类型/1.几何类型和GIS/config.json

+{
+  "node_id": "pg-3bbe12c0a19d4cb7a61dc0a20624ed89",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file

data/3.PostgreSQL高阶/2.高级数据类型/2.JSON和JSONB/config.json

+{
+  "node_id": "pg-69ad784e39c044d7a115cfd124e49ef1",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file

data/3.PostgreSQL高阶/2.高级数据类型/2.JSON和JSONB/json.json

+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "json.md",
+  "notebook_enable": false
+}
\ No newline at end of file

data/3.PostgreSQL高阶/2.高级数据类型/2.JSON和JSONB/json.md

+# JSON 和 JSONB 类型
+
+关于 JSON 和 JSONB 类型，哪句话是错的？
+
+## 答案
+
+JSON 就是 文本类型的封装，JSONB 是 JSON 的二进制压缩格式，JSON 和 JSONB 的功能与 TEXT 类型一样。
+
+## 选项
+
+### A
+
+JSONB 是推荐的 JSON 字段类型，更为高效。
+
+### B
+
+JSONB 可以通过 GIST 倒排索引优化对内部结构的查询。
+
+
+### C
+
+PostgreSQL JSON 和 JSONB 支持 JSON PATH表达式
+
+### D
+
+JSONB 和 文本可以有效兼容
+
+### E
+
+JSON 和 JSONB 与其它类型一样，不能部分修改，只能作为整体插入或更新
+

data/3.PostgreSQL高阶/2.高级数据类型/2.JSON和JSONB/match.md

+# 匹配
+
+表 book 的 meta 有类似如下结构：
+
+```json
+{
+  "author": [
+    "Mars Liu",
+    "Milly Lee"
+  ],
+  "ISBN": "xxxx-xxxx-xxxxxx",
+  "version": 1
+}
+```
+
+该字段有 gist 索引。
+
+如果我们想高效率的找到所有作者包含 Jim Gray 的书，应该如何查询？
+
+## 答案
+
+```postgresql
+select * from book where meta @> '{"author": ["Jim Gray"]}'::jsonb;
+```
+
+## 选项
+
+### A
+
+```postgresql
+select * from book where meta @> '["Jim Gray"]'::jsonb;
+```
+
+### A
+
+```postgresql
+select * from book where 'Jim Gray' in meta;
+```
+
+### B
+
+```postgresql
+select * from book where meta::text like '%Jim Gray%'; 
+```
+
+### C
+
+```postgresql
+select * from book having meta @> 'Jim Gray'
+```
+
+### D
+
+```postgresql
+select * from book where 'Jim Gray' in (meta #>> 'author');
+```

data/3.PostgreSQL高阶/2.高级数据类型/2.JSON和JSONB/tags.md

+# 标签
+
+现有一个表 sku:
+
+```postgresql
+create table sku(
+    id serial primary key ,
+    name text,
+    meta jsonb default '{}'::jsonb,
+    tags jsonb default '[]'::jsonb
+)
+```
+
+我们希望查找包含所有给定tag的商品，那么查询应该是：
+
+## 答案
+
+```postgresql
+select id, name, meta, tags from sku where tags @> $1;
+```
+
+## 选项
+
+### A
+
+```postgresql
+select id, name, meta, tags from sku where tags = $1;
+```
+
+### B
+
+```postgresql
+select id, name, meta, tags from sku where tags::text = $1;
+```
+
+### C
+
+```postgresql
+select id, name, meta, tags from sku where $1 in tags;
+```
+
+### D
+
+```postgresql
+select id, name, meta, tags from sku where tags in $1;
+```

data/3.PostgreSQL高阶/2.高级数据类型/3.函数/config.json

+{
+  "node_id": "pg-6dbbb44b41d347b58075a9155dfb8356",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file

data/3.PostgreSQL高阶/2.高级数据类型/3.函数/distinct.md

+# 去重
+
+下列函数中，有一个实现了合并两个 jsonb 对象并对其去重，是哪一项？
+
+## 答案
+
+```postgresql
+create function jsonb_distinct_merge(a jsonb, b jsonb) returns jsonb as
+$$
+    select jsonb_agg(distinct (value)) from jsonb_array_elements(a || b)
+$$ language sql
+```
+
+## 选项
+
+### A
+
+```postgresql
+create function jsonb_distinct_merge(a jsonb, b jsonb) returns jsonb as $$
+    select a || b
+$$ language sql
+```
+
+### B
+
+```postgresql
+create function jsonb_distinct_merge(a jsonb, b jsonb) returns jsonb as $$
+return jsonb_agg(distinct(value)) from jsonb_array_elements(a||b)
+$$ language sql
+```
+
+### C
+
+```postgresql
+create function jsonb_distinct_merge(a jsonb, b jsonb) returns jsonb as $$
+    return next jsonb_agg(distinct(value)) from jsonb_array_elements(a||b)
+$$ language sql
+```
+
+### D
+
+```postgresql
+create function jsonb_distinct_merge(a jsonb, b jsonb) returns jsonb as $$
+    select a + b;
+$$ language sql
+```
\ No newline at end of file

data/3.PostgreSQL高阶/2.高级数据类型/4.视图/config.json

+{
+  "node_id": "pg-532f8f84ea74493a9581e6bf720ebf78",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file

data/3.PostgreSQL高阶/2.高级数据类型/4.视图/view.md

+# 视图
+
+SmartMarket 公司的数据分析师，每天要执行一个固定的复杂查询，生成每日报表。我们准备将其创建为视图，这能够解决：
+
+1. 简化查询
+2. 降低查询时死锁的风险
+3. 大幅优化查询性能
+4. 限制权限
+
+## 答案
+
+1, 4
+
+## 选项
+
+### A
+
+1. 2, 3, 4
+
+### B
+
+1, 2, 3
+
+### C
+
+2, 3
+
+### D
+
+3, 4
\ No newline at end of file