MyBatis Package There is no getter for property named ' XXX ' in ' Class java.lang.String '

first, the problem found<select id= "Querystudentbynum" resulttype= "Student" parametertype= "string" >Select Num,name,phone from student<where> <ifTest = "Num!=null and num!=" >and num=#{num}</if></where></select>MyBatis query passed in a string argument, reported there is no Getter forProperty named ' Num ' in ' Class java.lang.String '. Second, solve the problem<select id= "Querystudentbynum" resulttype= "Student" parametertype= "string" >Select Num,name,phone from student<where> <ifTest = "_parameter!=null and_parameter!=" >and num=#{_parameter}</if></where></select>regardless of the parameter name, change to"_parameter". Third, cause analysis MyBatis default uses ONGL parsing parameters, so will automatically take the form of object tree String.num value, causing error. You can also public List methodName (@Param (Value= "num") method description parameter value of String num

MyBatis in the package there is the no getter for the property named ' XXX ' in ' Class java.lang.String '