1、增加(Insert):
xml
<insert id="insertUser" parameterType="User">
INSERT INTO user (id, name, age) VALUES (#{id}, #{name}, #{age})
</insert>
对应Java代码:
java
sqlSession.insert("insertUser", user);
sqlSession.commit();
2、删除(Delete):
xml
<delete id="deleteUserById" parameterType="int">
DELETE FROM user WHERE id = #{id}
</delete>
对应Java代码:
java
sqlSession.delete("deleteUserById", userId);
sqlSession.commit();
3、修改(Update):
xml
<update id="updateUser" parameterType="User">
UPDATE user SET name = #{name}, age = #{age} WHERE id = #{id}
</update>
对应Java代码:
java
sqlSession.update("updateUser", user);
sqlSession.commit();
4、查询(Select):
xml
<select id="getUserById" parameterType="int" resultType="User">
SELECT * FROM user WHERE id = #{id}
</select>
对应Java代码:
java
User user = sqlSession.selectOne("getUserById", userId);
在MyBatis中,可以使用动态SQL来构建灵活的增删改查语句,以应对不同的查询条件和业务需求。以下是一些常见的动态SQL语法示例:
5、动态条件查询:
xml