在我的数据库中,有一个表:
CREATE TABLE calibration_factor_pm1
(
sensor_id Integer REFERENCES sensor(id),
factor_a double precision NOT NULL,
factor_b double precision NOT NULL,
time_from_which_factor_is_used timestamp NOT NULL
)
并且由于将有其他类似的表,因此我想创建一个函数,以便可以向我传递有关要从哪个表中获取哪个因子(a或b)的信息。
我试图这样做:
private Double getCalibrationFactor(String sensorId, TableField<Record, TableImpl> factor, TableImpl PM, TableField<Record, TableImpl> sensorIdTableField, TableField<Record, TableImpl> timeFromWhichFactorIsUsed) {
Double calibrationFactorAPM1 = 1.0;
try {
calibrationFactorAPM1 = Double.valueOf(Database.create
.select(factor) //CalibrationFactorPm1.CALIBRATION_FACTOR_PM1.FACTOR_A
.from(PM) //CalibrationFactorPm1.CALIBRATION_FACTOR_PM1
.where(sensorIdTableField.equal(Integer.valueOf(sensorId)))
.orderBy(timeFromWhichFactorIsUsed.desc())
.fetchOne()
.getValue(0)
.toString());
} catch (NullPointerException e) {
System.out.println("DEBUG: Can't find calibration factor 'a' for this sensor");
e.printStackTrace();
}
}
但是,我在
Cannot resolve method 'equal(java.lang.Integer)'
行上得到了.where(sensorIdTableField.equal(Integer.valueOf(sensorId)))
。如何正确处理呢?
@编辑
这是equal()期望的:
最佳答案
我建议在方法签名中使用更多抽象类型,尤其是因为您似乎知道传递给方法的参数的类型。这样您就可以从jooq的类型安全功能中受益。
private Double getCalibrationFactor(String sensorId,
Field<Double> factor,
Table<?> PM,
Field<Integer> sensorIdTableField,
Field<Timestamp> timeFromWhichFactorIsUsed) {
Record1<Double> calibrationFactorAPM1 = Database.create
.select(factor) //CalibrationFactorPm1.CALIBRATION_FACTOR_PM1.FACTOR_A
.from(PM) //CalibrationFactorPm1.CALIBRATION_FACTOR_PM1
.where(sensorIdTableField.equal(Integer.valueOf(sensorId)))
.orderBy(timeFromWhichFactorIsUsed.desc())
.fetchOne();
return calibrationFactorAPM1 == null ? calibrationFactorAPM1.value1() : 1d;
}
您可能还希望传递
Integer sensorId
而不是String sensorId
。