net.sf.jsqlparser.statement.select.SubSelect cannot be cast to net.sf.jsqlparser.schema.Table

net.sf.jsqlparser.statement.select.SubSelect cannot be cast to net.sf.jsqlparser.schema.Table

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: java.lang.ClassCastException: net.sf.jsqlparser.statement.select.SubSelect cannot be cast to net.sf.jsqlparser.schema.Table
### The error may exist in file [D:javatargetclassesmappingDeviceMapper.xml]
### The error may involve com.parcel.mapper.DeviceMapper.findPage_mpCount
### The error occurred while executing a query
### Cause: java.lang.ClassCastException: net.sf.jsqlparser.statement.select.SubSelect cannot be cast to net.sf.jsqlparser.schema.Table

 代码示例

	SELECT
		d.id,
    CASE WHEN 
        d.agent_id = #{agentId}        #### 这里使用变量出错
    THEN
		0 
    ELSE 
        1 
	END sales 
	FROM
		pt_device d
		JOIN pt_device_group dg ON d.group_id = dg.id
		JOIN pt_device_server ds ON d.server_id = ds.id
		LEFT JOIN sys_user u1 ON d.agent_id = u1.id AND u1.type = 2
		
			and u1.parent_id = #{agentId}
		
		LEFT JOIN sys_user u2 ON d.user_id = u2.id AND u2.type = 4
		${ew.customSqlSegment}
 
解决方法 
// xml

	SELECT
		d.id
        ${ew.sqlSelect}            #### 使用 mybatisplus的常量拼接符
	FROM
		pt_device d
		JOIN pt_device_group dg ON d.group_id = dg.id
		JOIN pt_device_server ds ON d.server_id = ds.id
		LEFT JOIN sys_user u1 ON d.agent_id = u1.id AND u1.type = 2
		
			and u1.parent_id = #{agentId}
		
		LEFT JOIN sys_user u2 ON d.user_id = u2.id AND u2.type = 4
		${ew.customSqlSegment}


// java
queryWrapper.select(", case when d.agent_id = " + agentId + " then 0 else 1 end sales");