Database-Homework

Homework assignments of An Introduction to Database System

Homework 1

2020.3.3

• 关系数据模型
• 完整性规则

Homework 2

3.10

• 关系代数

Homework 3

3.25

• SQL 查询

Homework 4

4.8

• 关系模式

Homework 5

4.22

• ER 模型实例
• TikZ ER 模型图

Homework 6

4.26

• 数据库数据结构
  • B+ 树
  • 个人完成的用以绘制 B+ 树的 TikZ 包，用法
  • 可扩展 Hash

Homework 7

5.5

• 事务处理

Homework 8

5.19

• 事务调度

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tikz-B+Tree 包

一个简单的用于绘制 3-4 B+ 树结点的 TikZ 包

1. 引用

\usepackage{tikz-B+Tree}

2. 提供

• node style B+node
  • anchor
    • ptr1
    • ptr2
    • ptr3
    • ptr4
    • proc
• path style Pointer
• alias \B+{#1|#2|#3}

3. 实例

\documentclass{standalone}
\usepackage{tikz-B+Tree}
\begin{document}
\begin{tikzpicture}[every node/.style = {B+node, draw}, every path/.style = {Pointer}]

    \node at(  0  ,   0  ) (A1) {\B+(13|{\color{blue}37}|)};
    \node at(-12em,  -6em) (B1) {\B+(7||)};
    \node at(  0em,  -6em) (B2) {\B+({\color{blue}23}|{\color{blue}31}|)};
    \node at( 12em,  -6em) (B3) {\B+({\color{blue}43}||)};
    \node at(-18em, -12em) (C1) {\B+(2|3|5)};
    \node at(-12em, -12em) (C2) {\B+(7|11|)};
    \node at( -6em, -12em) (C3) {\B+(13|17|19)};
    \node at(  0em, -12em) (C4) {\B+(23|29|)};
    \node at(  6em, -12em) (C5) {\B+({\color{blue}31}|{\color{red}36}|)};
    \node at( 12em, -12em) (C6) {\B+({\color{blue}37}|{\color{blue}41}|)};
    \node at( 18em, -12em) (C7) {\B+(43|47|)};

    \foreach \i in {1, 2, 3}
        \draw (A1.ptr\i) to (B\i);
    \foreach \i in {1, 2}
        \draw (B1.ptr\i) to (C\i);
    \foreach \i [evaluate=\i as \j using int(\i+2)] in {1, ..., 3}
        \draw (B2.ptr\i) to (C\j);
    \foreach \i [evaluate=\i as \j using int(\i+5)] in {1, 2}
        \draw (B3.ptr\i) to (C\j);
    \foreach \i/\j in {1/1, 1/2, 1/3, 2/1, 2/2, 3/1, 3/2, 3/3, 4/1, 4/2, 5/1, 5/2, 6/1, 6/2, 7/1, 7/2}
        \draw (C\i.ptr\j) -- +(0, -1);
    \foreach \i [evaluate=\i as \j using int(\i+1)] in {1, ..., 6}
        \draw (C\i.ptr4) to[out = 0, in = 180] (C\j.proc);

    \draw [blue] (C5.ptr4) to[out = 0, in = 180] (C6.proc);

\end{tikzpicture}
\end{document}