MyBatis的parameterType是干什么的

MyBatis的parameterType是用来指定传入SQL语句的参数类型。它可以是一个JavaBean、Map、基本数据类型等，用来告诉MyBatis如何将传入的参数转换成SQL语句中的占位符。例如，如果parameterType指定为一个JavaBean，那么MyBatis会将JavaBean中的属性值与SQL语句中的占位符一一对应，从而完成SQL语句的执行。如果parameterType指定为Map，那么MyBatis会将Map中的key与SQL语句中的占位符一一对应，从而完成SQL语句的执行。

相关问题

mybatis parameterType

MyBatis parameterType is a required attribute in the `<insert>`, `<update>`, `<delete>`, and `<select>` statements. It specifies the Java type of the parameter(s) that are passed to the SQL statement.

The parameterType can be a fully qualified class name or an alias defined in the MyBatis configuration file. It tells MyBatis how to map the input parameters to the placeholders in the SQL statement.

For example, if you have a parameterType of "com.example.User" in your `<insert>` statement, MyBatis will expect a single object of type User to be passed as the parameter when executing that statement.

Here's an example of how to use parameterType in a MyBatis XML mapper file:

<insert id="insertUser" parameterType="com.example.User">
  INSERT INTO users (id, name, age) VALUES (#{id}, #{name}, #{age})
</insert>

In this example, the parameterType is set to "com.example.User", and the properties of the User object (`id`, `name`, and `age`) are mapped to the corresponding columns in the `users` table using MyBatis's parameter mapping feature.

It's important to ensure that the parameterType matches the actual type of the parameter passed to the statement, as MyBatis relies on this information for proper mapping and type conversion.

mybatis parametertype

MyBatis 的 parameterType 指的是在执行 SQL 语句时使用的参数的类型。它可以是一个 Java 类，例如 String 或 Integer，也可以是一个 POJO（Plain Old Java Object，普通的 Java 对象）。MyBatis 会根据 parameterType 的类型来自动映射参数。