在写insert子句的时候,由于不知道需要插入多少字段,mybatis通过prefix,suffix,suffixOverrides很好的解决了该问题,实现了动态insert语句。
用这种动态插入时<if test=""></test>这里test的字段一定不要写错,本来直接写字段名就可以了,写错为#字段名 就不起作用了
<insert id="insertSelective" parameterType="com.bootdo.system.domain.LogDO">
insert into sys_log
<trim prefix="(" suffix=")" suffixOverrides=",">
<if test="id != null">
id,
</if>
<if test="userId != null">
user_id,
</if>
<if test="username != null">
username,
</if>
<if test="operation != null">
operation,
</if>
<if test="time != null">
time,
</if>
<if test="method != null">
method,
</if>
<if test="params != null">
params,
</if>
<if test="ip != null">
ip,
</if>
<if test="gmtCreate != null">
gmt_create,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides=",">
<if test="id != null">
#{id,jdbcType=BIGINT},
</if>
<if test="userId != null">
#{userId,jdbcType=BIGINT},
</if>
<if test="username != null">
#{username,jdbcType=VARCHAR},
</if>
<if test="operation != null">
#{operation,jdbcType=VARCHAR},
</if>
<if test="time != null">
#{time,jdbcType=INTEGER},
</if>
<if test="method != null">
#{method,jdbcType=VARCHAR},
</if>
<if test="params != null">
#{params,jdbcType=VARCHAR},
</if>
<if test="ip != null">
#{ip,jdbcType=VARCHAR},
</if>
<if test="gmtCreate != null">
#{gmtCreate,jdbcType=TIMESTAMP},
</if>
</trim>
</insert>
顺便记一下批量插入
Mapper接口中提供
public void batchSave(List<Emp> empList);
Mapper.xml提供
<insert id="batchSave">
into t_emp(emp_name,emp_email,dept_id) VALUES
<foreach collection="list" item="emp" separator=",">
(#{emp.empName}, #{emp.empEmail}, #{emp.deptId})
</foreach>
</insert>