MyBatis Dynamic SQL use, pass in Parameter map key judgment

<SelectID=""ParameterType= "Map"Resultmap= "Commodityresultmap" >SELECT c.id c_id,c.variety_id,c.nickname c_nickname,c.description c_description,c.ordinaryprice c_ordinaryPric E,c.memberprice C_memberprice,c.path c_path,v.id v_id,v.nickname v_nickname from commodity c INNER JOIN VA Riety V on c.variety_id=v.id where 1=1<!--_parameter.containskey (' key ') Action: Determine if the key exists return value Boolean #{key} take the corresponding value! must correspond to three key values, otherwise the value cannot be taken -             <ifTest= "_parameter.containskey (' Varietyid ')">and V.id=#{varietyid}</if>    </Select>

• The benefits of this approach can be long-term queries.

MyBatis Dynamic SQL use, pass in Parameter map key judgment