数据库连接池之_DButils
生活随笔
收集整理的這篇文章主要介紹了
数据库连接池之_DButils
小編覺得挺不錯(cuò)的,現(xiàn)在分享給大家,幫大家做個(gè)參考.
1 // 這個(gè)是在添加數(shù)據(jù)
2 @Test
3 public void demo1() {
4 QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());
5 String sql = "insert into Book values(?,?)";
6 try {
7 int num = qr.update(sql, 26, "明朝那些事");
8 if (num > 0) {
9 System.out.println("添加成功");
10 } else {
11 System.out.println("添加失敗");
12 }
13 } catch (SQLException e) {
14 // TODO Auto-generated catch block
15 e.printStackTrace();
16 }
17 }
18
19 // 修改數(shù)據(jù)
20 @Test
21 public void demo2() {
22 QueryRunner queryRunner = new QueryRunner(JDBCUtils.getDataSource());
23 try {
24 String sql = "update Book set bname=? where id=?";
25 int num = queryRunner.update(sql, "史記", 29);
26 if (num > 0) {
27 System.out.println("添加成功");
28 } else {
29 System.out.println("添加失敗");
30 }
31 } catch (Exception e) {
32 e.printStackTrace();
33 }
34 }
35
36 // 下面的是查詢語句
37 // 將數(shù)據(jù)表中的第一條數(shù)據(jù)封裝成object
38 @Test
39 public void demo3() {
40 QueryRunner queryRunner = new QueryRunner(JDBCUtils.getDataSource());
41 try {
42 String sql = "select * from Book";
43 Object[] objects = queryRunner.query(sql, new ArrayHandler());
44
45 System.out.println(Arrays.toString(objects));
46 } catch (Exception e) {
47 e.printStackTrace();
48 }
49 }
50
51 //將數(shù)據(jù)表中的每一條數(shù)據(jù)封裝成object new ArrayListHandler()
52 @Test
53 public void demo4(){
54 QueryRunner queryRunner=new QueryRunner(JDBCUtils.getDataSource());
55 try {
56 String sql="select * from Book";
57 List<Object[]> list=queryRunner.query(sql,new ArrayListHandler());
58
59 for(Object[] objects:list){
60 System.out.println(Arrays.toString(objects));
61 }
62
63 } catch (Exception e) {
64 e.printStackTrace();
65 }
66 }
67
68
69 //把數(shù)據(jù)表中的第一條數(shù)據(jù)封裝成JavaBean實(shí)體類對象 BeanHandler
70 @Test
71 public void demo5(){
72 QueryRunner queryRunner=new QueryRunner(JDBCUtils.getDataSource());
73 try {
74 String sql="select * from Book";
75 Book list=queryRunner.query(sql,new BeanHandler<>(Book.class));
76
77 System.out.println(list.toString());
78 } catch (Exception e) {
79 e.printStackTrace();
80 }
81 }
82
83
84 //把數(shù)據(jù)表中的每一條數(shù)據(jù)封裝成JavaBean實(shí)體類對象 BeanListHandler
85 @Test
86 public void demo6(){
87 QueryRunner queryRunner=new QueryRunner(JDBCUtils.getDataSource());
88 try {
89 String sql="select * from Book";
90 List<Book> list=queryRunner.query(sql,new BeanListHandler<>(Book.class));
91
92 for(Book book:list)
93 System.out.println(book.toString());
94 } catch (Exception e) {
95 e.printStackTrace();
96 }
97 }
98
99 //把數(shù)據(jù)表中的第一條數(shù)據(jù)封裝成Map集合 ,鍵:列名 值:該列的值 new MapHandler()
100 @Test
101 public void demo7(){
102 QueryRunner queryRunner=new QueryRunner(JDBCUtils.getDataSource());
103 try {
104 String sql="select * from Book";
105 Map<String,Object > map=queryRunner.query(sql,new MapHandler());
106
107 System.out.println(map);
108 } catch (Exception e) {
109 e.printStackTrace();
110 }
111 }
112
113 //把數(shù)據(jù)表中的每一條數(shù)據(jù)封裝成Map集合 ,鍵:列名 值:該列的值 new MapListHandler()
114 @Test
115 public void demo8(){
116 QueryRunner queryRunner=new QueryRunner(JDBCUtils.getDataSource());
117 try {
118 String sql="select * from Book";
119 List<Map<String,Object >>list=queryRunner.query(sql,new MapListHandler());
120 for(Map<String,Object>map:list)
121 System.out.println(map);
122 } catch (Exception e) {
123 e.printStackTrace();
124 }
125 }
126
127 // ColunmListHandler: 把數(shù)據(jù)表中的沒一條數(shù)據(jù)封裝成 Map集合, 鍵:列名 值:該列的值 , 然后把每一行的Map集合裝入到一個(gè)List集合中.
128 @Test
129 public void demo9() {
130 // 1. 獲取可以執(zhí)行SQL語句的對象: QueryRunner
131 QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());
132 // 2. 編寫需要執(zhí)行的SQL語句
133 String sql = "select * from Book;";
134 // 3. 執(zhí)行SQL語句, 獲取結(jié)果集
135 try {
136 List<Object> list = qr.query(sql, new ColumnListHandler("bname"));
137 System.out.println(list);
138 } catch (SQLException e) {
139 e.printStackTrace();
140 }
141 }
142
143 // ScalarHandler: 把數(shù)據(jù)表中的沒一條數(shù)據(jù)封裝成 Map集合, 鍵:列名 值:該列的值 , 然后把每一行的Map集合裝入到一個(gè)List集合中.
144 @Test
145 public void demo10() {
146 // 1. 獲取可以執(zhí)行SQL語句的對象: QueryRunner
147 QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());
148 // 2. 編寫需要執(zhí)行的SQL語句
149 String sql = "select count(*) from Book;";
150 // 3. 執(zhí)行SQL語句, 獲取結(jié)果集
151 try {
152 Object obj = qr.query(sql, new ScalarHandler());
153 System.out.println(obj);
154 } catch (SQLException e) {
155 e.printStackTrace();
156 }
157 }
158
159 // KeyedHandler: 把數(shù)據(jù)表中的沒一條數(shù)據(jù)封裝成 Map集合, 鍵:列名 值:該列的值 , 然后把每一行的Map集合裝入到一個(gè)List集合中.
160 @Test
161 public void demo11() {
162 // 1. 獲取可以執(zhí)行SQL語句的對象: QueryRunner
163 QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());
164 // 2. 編寫需要執(zhí)行的SQL語句
165 String sql = "select * from Book;";
166 // 3. 執(zhí)行SQL語句, 獲取結(jié)果集
167 try {
168 Map<Object, Map<String, Object>> map = qr.query(sql, new KeyedHandler("bname"));
169 for (Object key : map.keySet()) {
170 System.out.println(key + "..." + map.get(key));
171 }
172
173 } catch (SQLException e) {
174 e.printStackTrace();
175 }
176 }
?
轉(zhuǎn)載于:https://www.cnblogs.com/zhuguangzhe/p/7458260.html
與50位技術(shù)專家面對面20年技術(shù)見證，附贈技術(shù)全景圖總結(jié)
以上是生活随笔為你收集整理的数据库连接池之_DButils的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。
- 上一篇： STL空间配置器
- 下一篇： 关于Lambda和匿名内部类