querydsl - column name 에 따른 조회 쿼리

repository

import java.util.List;

public interface ProductInfoRepository {

    List<ProductInfoResult> findProductInfoWithGroup(String columnName, String factoryCode);
}

@Repository
@RequiredArgsConstructor
public class ProductInfoCustomRepository implements ProductInfoRepository {

    private final JPAQueryFactory queryFactory;
    private final QProductInfo qProductInfo;

    public List<ProductInfoResult> findProductInfoWithGroup(String columnName, String factoryCode) {
        CaseBuilder caseBuilder = new CaseBuilder();
        StringPath attributeA = createDynamicColumn(columnName);

        BigDecimal threshold80 = Expressions.numberTemplate("{0} + {1} * 0.8", attributeA, subQuery().diff);
        BigDecimal threshold60 = Expressions.numberTemplate("{0} + {1} * 0.6", attributeA, subQuery().diff);
        BigDecimal threshold40 = Expressions.numberTemplate("{0} + {1} * 0.4", attributeA, subQuery().diff);
        BigDecimal threshold20 = Expressions.numberTemplate("{0} + {1} * 0.2", attributeA, subQuery().diff);

        return queryFactory
                .select(
                        qProductInfo.productQuantity.as("productQuantity"),
                        attributeA.eq(columnName).as("attributeA"),
                        caseBuilder
                                .when(attributeA.goe(threshold80)).then("A")
                                .when(attributeA.lt(threshold80).and(attributeA.goe(threshold60))).then("B")
                                .when(attributeA.lt(threshold60).and(attributeA.goe(threshold40))).then("C")
                                .when(attributeA.lt(threshold40).and(attributeA.goe(threshold20))).then("D")
                                .otherwise("E").as("groupName")
                )
                .from(qProductInfo, subQuery())
                .where(qProductInfo.processCode.eq(factoryCode).and(attributeA.isNotNull()))
                .fetch();
    }

    private QProductInfo subQuery() {
        QProductInfo subQuery = new QProductInfo("sub_query");
        return subQuery;
    }

    private StringPath createDynamicColumn(String columnName) {
        switch (columnName) {
            case "column4":
                return QProductInfo.column4;
            case "column5":
                return QProductInfo.column5;
            case "column6":
                return QProductInfo.column6;
            // ... (column7 ~ column24)
            default:
                throw new IllegalArgumentException("[FAIL] 지원하지않는컬럼 " + columnName);
        }
    }
}