import java.util.Iterator;
2 import java.util.Map;
3 import java.util.Set;
4
5 public class SQLUtil {
6 public static String sqlSelect = ""
;
7
8 public static String selectQuerySQL(Map<String, Object>
map, String tableName) {
9 if (map.isEmpty() || map.size() == 0
) {
10 sqlSelect = "select*from" +
tableName;
11 }
else {
12 sqlSelect = "select*from" + tableName + "where"
;
13 Set set =
map.keySet();
14 Iterator iterator =
set.iterator();
15 int index = 0
;
16 while (iterator.hasNext()) {
17 String key =
(String) iterator.next();
18 Object value =
map.get(key);
19 if (value
instanceof String) {
20 value = "‘" + value + "‘"
;
21 }
22 index++
;
23 if ((index == 1 && map.size() == 1) || map.size() ==
index) {
24 sqlSelect += key + "=" + value + " "
;
25 }
else {
26 sqlSelect += key + "=" + value + " " + "and" + " "
;
27 }
28 }
29 }
30 System.out.println("待执行的select SQL："+
sqlSelect);
31 return sqlSelect;
32 }
33 public static String insertSQL(Map<String,Object>
map){
34 Iterator<String> iterator =
map.keySet().iterator();
35 StringBuilder sqlTable=
new StringBuilder("insert into"
);
36 StringBuilder sqlKey=
new StringBuilder("("
);
37 StringBuilder sqlVaule=
new StringBuilder("value("
);
38 while (iterator.hasNext()){
39 String key=
iterator.next();
40 if(map.get(key).toString()==
null||map.get(key).toString().length()==0
){
41 iterator.remove();
42 }
else {
43 if (key.equals("tableName"
)){
44 sqlTable.append(map.get(key));
45 }
else {
46 sqlKey.append(key+","
);
47 sqlVaule.append(map.get(key)+","
);
48 }
49 }
50 }
51 sqlTable.append(sqlKey.toString().substring(0,sqlKey.toString().lastIndexOf(","))+")").append(sqlVaule.toString().substring(0,sqlVaule.lastIndexOf(","))+")"
);
52 String sql=
sqlTable.toString();
53 System.out.println("待执行的insert SQL："+
sql);
54 return sql;
55 }
56 /*此为以上方法的用法，可以忽略*/
57 /*public static void main(String[] args) {
58 //调用select的方法
59 Map<String,Object> map=new HashMap<>();
60 map.put("字段名","具体的值");
61 String tableName="表名";
62 System.out.println(selectQuerySQL(map,tableName).toString());
63 //调用insert的方法
64 Map<String,Object> map=new HashMap<>();
65 map.put("字段名","具体的值");
66 map.put("tableName","这里最后添加表名");
67 String sql = insertSQL(map);
68 PreparedStatement statment = connection.prepareStatement(sql);
69 statment.execute(sql);//这里是执行SQL语句，需要借助JDBCUtil中的Connection得到connection
70 }*/
71 }
动态SQL拼接，select，insert的写法
标签：class statement exe shm value remove insert ring string
