SQL语句的拼凑

 1 StringBuilder sql = new StringBuilder("SELECT * FROM t_customer WHERE 1=1");
 2             /*
 3              * 2. 判断条件，完成向sql中追加where子句
 4              */
 5             /*
 6              * 3. 创建一个ArrayList，用来装载参数值
 7              */
 8             List<Object> params = new ArrayList<Object>();
 9             String cname = criteria.getCname();
10             if(cname != null && !cname.trim().isEmpty()) {
11                 sql.append(" and cname like ?");
12                 params.add("%" + cname + "%");
13             }
14 
15             String gender = criteria.getGender();
16             if(gender != null && !gender.trim().isEmpty()) {
17                 sql.append(" and gender=?");
18                 params.add(gender);
19             }
20 
21             String cellphone = criteria.getCellphone();
22             if(cellphone != null && !cellphone.trim().isEmpty()) {
23                 sql.append(" and cellphone like ?");
24                 params.add("%" + cellphone + "%");
25             }
26 
27             String email = criteria.getEmail();
28             if(email != null && !email.trim().isEmpty()) {
29                 sql.append(" and email like ?");
30                 params.add("%" + email + "%");
31             }