mybatis in 使用

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SELECT alarm_name as alarmName, alarm_time as alarmTime, alarm_main_level as alarmLevel, device_name as deviceName, ent_name as entName FROM t_device_alarm <where> delete_flag = 0 <if test='alarmLevel != null and alarmLevel != ""'> AND alarm_main_level in (<![CDATA[ ${alarmLevel} ]]>) </if> </where>
UNION ALL

SELECT alarm_name as alarmName, alarm_date as alarmTime, alarm_main_level as alarmLevel, device_name as deviceName, ent_name as entName FROM t_device_alarm_history <where> delete_flag = 0 <if test='alarmLevel != null and alarmLevel != ""'> AND alarm_main_level in (<![CDATA[ ${alarmLevel} ]]>) </if> </where> ORDER BY alarmTime DESC </select>

SELECT
name, 
time,
level, 
device_name, 
ent_name
FROM t_device
<where> 
delete_flag = 0 
<if test='level != null and level != ""'>
 AND level in (<![CDATA[ ${level} ]]>) 
</if> 
</where>
UNION ALL

SELECT 
name,
time, 
level, 

device_name, 

ent_name
FROM t_history
<where> delete_flag = 0 
<if test='level != null and level != ""'> 
AND level in (<![CDATA[ ${level} ]]>) </if> 
</where> 
ORDER BY time DESC
 </select>

 

 

将list[string] 中字符串拼接成 一个大字符串，以他作为条件 String ss = String.join(","list);

连接中foreach 方法，单个可以运行，如果使用union all 之后，两个foreach 共用一个入参list则会报错，改为字符串最佳

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