// 这个是在添加数据
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("添加失败"
);
12 }
13 }
catch (SQLException e) {
14 // TODO Auto-generated catch block
15 e.printStackTrace();
16 }
17 }
18
19 // 修改数据
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, "史记", 29
);
26 if (num > 0
) {
27 System.out.println("添加成功"
);
28 }
else {
29 System.out.println("添加失败"
);
30 }
31 }
catch (Exception e) {
32 e.printStackTrace();
33 }
34 }
35
36 // 下面的是查询语句
37 // 将数据表中的第一条数据封装成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 //将数据表中的每一条数据封装成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 //把数据表中的第一条数据封装成JavaBean实体类对象 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 //把数据表中的每一条数据封装成JavaBean实体类对象 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 //把数据表中的第一条数据封装成Map集合 ,键:列名 值:该列的值 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 //把数据表中的每一条数据封装成Map集合 ,键:列名 值:该列的值 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: 把数据表中的没一条数据封装成 Map集合, 键:列名 值:该列的值 , 然后把每一行的Map集合装入到一个List集合中.
128 @Test
129 public void demo9() {
130 // 1. 获取可以执行SQL语句的对象: QueryRunner
131 QueryRunner qr =
new QueryRunner(JDBCUtils.getDataSource());
132 // 2. 编写需要执行的SQL语句
133 String sql = "select * from Book;"
;
134 // 3. 执行SQL语句, 获取结果集
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: 把数据表中的没一条数据封装成 Map集合, 键:列名 值:该列的值 , 然后把每一行的Map集合装入到一个List集合中.
144 @Test
145 public void demo10() {
146 // 1. 获取可以执行SQL语句的对象: QueryRunner
147 QueryRunner qr =
new QueryRunner(JDBCUtils.getDataSource());
148 // 2. 编写需要执行的SQL语句
149 String sql = "select count(*) from Book;"
;
150 // 3. 执行SQL语句, 获取结果集
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: 把数据表中的没一条数据封装成 Map集合, 键:列名 值:该列的值 , 然后把每一行的Map集合装入到一个List集合中.
160 @Test
161 public void demo11() {
162 // 1. 获取可以执行SQL语句的对象: QueryRunner
163 QueryRunner qr =
new QueryRunner(JDBCUtils.getDataSource());
164 // 2. 编写需要执行的SQL语句
165 String sql = "select * from Book;"
;
166 // 3. 执行SQL语句, 获取结果集
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 }
数据库连接池之_DButils
标签：keyset 实体 编写 set [] scala pre cat 数据表
