select * from A where 1=1
${if(LTY == "", "",
"AND nurse_type = " +
case(LTY,
"特需护理", "0",
"一级护理", "1",
"二级护理", "2",
"三级护理", "3"))}
${if(len(LTY)=0,"","and nurse_type ='"+SWITCH(LTY,
"三级护理", "3")+"'")}