下拉框参数为空选择全部-https://help.fanruan.com/finereport/doc-view-2394.html
——————文档有实例和视频详解,请查阅;
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WHERE 1=1
${IF(LEN(参数)==0,"","and 字段='"+ 参数 +"'")}
举个例子:
(1 = (CASE WHEN '${Month}' = '' or '${Month}' is null
THEN 1 ELSE 0 END) OR 月份='${Month}')