mybatis的example的or
时间: 2023-11-12 07:06:44 浏览: 44
MyBatis的Example类提供了一种方便的方式来构建动态的SQL查询条件。在Example中,可以使用or方法来构建OR条件。
下面是一个示例代码,演示如何使用Example的or方法:
```java
Example example = new Example(User.class);
Example.Criteria criteria1 = example.createCriteria();
criteria1.andEqualTo("name", "Alice");
Example.Criteria criteria2 = example.createCriteria();
criteria2.andEqualTo("name", "Bob");
example.or(criteria2);
List<User> users = userMapper.selectByExample(example);
```
在上面的示例中,我们创建了一个User类的Example对象,并创建了两个Criteria对象,分别用于设置name等于"Alice"和"name"等于"Bob"的条件。然后,使用example的or方法将第二个条件添加到OR条件中。最后,通过调用selectByExample方法执行查询。
这样就可以构建出一个查询条件为(name='Alice' OR name='Bob')的动态SQL查询语句。
相关问题
mybatis example $ sql注入
MyBatis provides various features to prevent SQL injection attacks. Here are a few examples:
1. Parameterized queries: MyBatis uses parameterized queries, which separate the SQL code from the user input. This approach helps prevent SQL injection by treating user input as parameters rather than concatenating them directly into the SQL statement.
2. Dynamic SQL tags: MyBatis allows the use of dynamic SQL tags, such as `<if>`, `<choose>`, and `<foreach>`, which help in constructing SQL queries dynamically. These tags automatically handle proper escaping and parameterization of user input.
3. Type handlers: MyBatis employs type handlers to convert Java types to and from database types. These handlers ensure that user input is properly escaped or sanitized when passing it to the database, minimizing the risk of SQL injection attacks.
It is important to properly utilize these features and follow best practices when using MyBatis to prevent SQL injection vulnerabilities.
mybatis plus or括号
MyBatis Plus supports the OR condition using the `or` method provided by the `QueryWrapper` class. To use OR conditions with parentheses, you can chain multiple `or` methods together.
Here's an example:
```java
QueryWrapper<Entity> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("column1", value1)
.or()
.eq("column2", value2)
.or()
.nested(wrapper -> wrapper.eq("column3", value3).ne("column4", value4));
```
In the above example, `eq` represents the equal condition, `ne` represents the not equal condition, and `nested` is used to create a nested condition with parentheses.
You can adjust the conditions and column names based on your requirements.