Mybatis常用标签使用

trim元素的主要功能是可以在自己包含的内容前加上某些前缀，也可以在其后加上某些后缀，与之对应的属性是prefix和suffix；可以把包含内容的首部某些内容覆盖，即忽略，也可以把尾部的某些内容覆盖，对应的属性是prefixOverrides和suffixOverrides；

<insert id="operatorLog" parameterType="com.oa.model.wxlog.WxLog">
        INSERT INTO sdb_oa_operator_log
        <trim prefix="(" suffix=")" suffixOverrides="," >
            <if test="open_id!='' and open_id != null">
            open_id,
            </if>
                <if test="operatortime!='' and operatortime != null">
            operatortime,
            </if>
                <if test="operatortype!='' and operatortype != null">
            operatortype,
            </if>
                <if test="operatorcont!='' and operatorcont != null">
            operatorcont,
            </if>
                <if test="ip!='' and ip != null">
            ip,
            </if>
        </trim>
        <trim prefix="values(" suffix=")" suffixOverrides="," >
            <if test="open_id!='' and open_id != null">
            #{open_id},
            </if>
                <if test="operatortime!='' and operatortime != null">
            #{operatortime},
            </if>
                <if test="operatortype!='' and operatortype != null">
            #{operatortype},
            </if>
                <if test="operatorcont!='' and operatorcont != null">
            #{operatorcont},
            </if>
                <if test="ip!='' and ip != null">
            #{ip},
            </if>
        </trim>
    </insert>

Mybatis 配置文件 useGeneratedKeys 参数只针对 insert 语句生效，默认为 false。
当设置为 true 时，表示如果插入的表以自增列为主键，则允许 JDBC 支持自动生成主键，并可将自动生成的主键返回。

<insert id="saveMain" parameterType="java.util.HashMap" keyProperty="id" useGeneratedKeys="true">
        insert into <include refid="tableName"></include>(
            <include refid="Field"></include>
        ) values (
            <include refid="FieldValue"></include>
        )
</insert>

--------------Mybatis 拼接like ---

 and date_format(company.create_time,'%Y-%m-%d %H:%i:%s') LIKE CONCAT('%', '${params.create_time}', '%')

----------------mybatis 判断参数要加.toString()---

<if test="params.selectTime =='2'.toString() ">