报错信息如下：
when useing jsqlparser parser this sql then throw a exception:Encountered unexpected token: "if" "IF"
Caused by: net.sf.jsqlparser.JSQLParserException
at net.sf.jsqlparser.parser.CCJSqlParserUtil.parseStatements(CCJSqlParserUtil.java:137)
at com.baomidou.mybatisplus.core.parser.AbstractJsqlParser.parser(AbstractJsqlParser.java:60)
... 47 more
Caused by: net.sf.jsqlparser.parser.ParseException: Encountered unexpected token: "if" "IF"
at line 10, column 9.原因
使用Mybatis 进行使用，采用JSQLParser 对sql进行解析，但是低版本的不支持IF(“”,””,””)函数，可以使用case when 进行代替
例如：
IF(lvi.id is not null,1,0) as usefulVideo,
IF(pspsv.id is not null,1,0) as uploadedVideo可以替换为：
CASE
WHEN lvi.id is NULL THEN
0 ELSE 1
END AS usefulVideo,
CASE
WHEN pspsv.id is NULL THEN
0 ELSE 1
END AS uploadedVideo
