MyBatis使用@SelectProvider拼接sql語句

若是使用MyBatis註解方式寫sql，又想要XML寫法的判斷入參拼接條件，能夠經過@SelectProvider方式實現。

新建Provider

public class RateProvider {
    private final String table_name = "rate_finish";

    public String getFinishRate(Map<String, Object> para) {
        String sql = "SELECT homework_type,device_type,`level`,finish_count,count,create_at FROM rate_finish ";
        sql += "WHERE 1=1 ";
        if (para.get("deviceType") != null && !StringUtils.isEmpty(para.get("deviceType").toString())) {
            sql += "AND device_type = '" + para.get("deviceType").toString() + "' ";
        }
        if (para.get("homeworkType") != null && !StringUtils.isEmpty(para.get("homeworkType").toString())) {
            sql += "AND homework_type = '" + para.get("homeworkType").toString() + "' ";
        }
        if (para.get("date") != null && !StringUtils.isEmpty(para.get("date").toString())) {
            sql += "AND create_at = '" + para.get("date").toString() + "' ";
        }
        sql += "ORDER BY homework_type,device_type,`level`";
        return sql;
    }
}

這裏的para會包含6個值，也就是2倍的入參參數，能夠經過key方式或者index方式獲取對應參數。

新建Entity

public class RateFinish extends AbstractModel {

    private int id;
    private String deviceType;
    private String level;
    private String finishCount;
    private String count;
    private String homeworkType;
    private String createAt;

編寫Mapper方法

@SelectProvider(type = RateProvider.class, method = "getFinishRate")
    @Results({
            @Result(property = "homeworkType", column = "homework_type"),
            @Result(property = "deviceType", column = "device_type"),
            @Result(property = "level", column = "level"),
            @Result(property = "finishCount", column = "finish_count"),
            @Result(property = "count", column = "count"),
            @Result(property = "createAt", column = "create_at")
    })
    List<RateFinish> getFinishRate(
            @Param("deviceType") String deviceType,
            @Param("homeworkType") String homeworkType,
            @Param("date") String date);