如何在SQL中获得最低的唯一出价

时间:2018-12-11 13:25:13

标签: php sql mariadb

我该添加什么查询以获得最低的唯一出价?

SELECT auction.title, auction.auction_id, bid.name, bid.price
FROM auction INNER JOIN
     bid
     ON auction.auction_id = bid.auction_id

1 个答案:

答案 0 :(得分:2)

我们可以尝试将<?xml version="1.0" encoding="utf-8"?> <ScrollView xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/svInterests" style="@style/joyship_page.scroll" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@color/joyship_background" android:fadeScrollbars="true" android:orientation="vertical" android:paddingBottom="@dimen/marginMainMinusShadow" android:scrollbarThumbVertical="@color/colorBrand"> <android.support.constraint.ConstraintLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <android.support.v7.widget.AppCompatImageButton android:id="@+id/btnTopInterestsBack" style="@style/joyship_clickableIconPadded" android:layout_width="@dimen/iconArrowNarrowEnlarged" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:srcCompat="@drawable/ib_arrow_backward" /> <android.support.v7.widget.AppCompatImageButton android:id="@+id/btnTopInterestsForward" style="@style/joyship_clickableIconPadded" android:layout_width="@dimen/iconArrowNarrowEnlarged" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintTop_toTopOf="parent" app:srcCompat="@drawable/ib_arrow_forward" /> <TextView android:id="@+id/tvHeaderTopActivities" style="@style/joyship_text.header" android:layout_marginTop="@dimen/halfMainMargin" android:fontFamily="@font/josefin_sans_regular" android:text="@string/headerInterestSelection" android:textSize="@dimen/fontSizeXl" app:layout_constraintTop_toBottomOf="@id/btnTopInterestsBack" tools:ignore="SpUsage" /> <android.support.v7.widget.LinearLayoutCompat style="@style/joyship_viewgroup.card" android:layout_marginTop="@dimen/marginBeneathOnboardingHeaderShadow" app:layout_constraintBottom_toBottomOf="parent" android:orientation="vertical" app:layout_constraintTop_toBottomOf="@id/tvHeaderTopActivities"> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbMusic" style="@style/joyship_control.checkbox" android:layout_marginTop="@dimen/halfMainMargin" android:text="@string/interest_music" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbTv" style="@style/joyship_control.checkbox" android:text="@string/interest_tv" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbMovies" style="@style/joyship_control.checkbox" android:text="@string/interest_movies" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbGames" style="@style/joyship_control.checkbox" android:text="@string/interest_games" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbReading" style="@style/joyship_control.checkbox" android:text="@string/interest_reading" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbTravel" style="@style/joyship_control.checkbox" android:text="@string/interest_travel" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbSports" style="@style/joyship_control.checkbox" android:text="@string/interest_sports" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbExercise" style="@style/joyship_control.checkbox" android:text="@string/interest_exercise" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbParty" style="@style/joyship_control.checkbox" android:text="@string/interest_party" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbFood" style="@style/joyship_control.checkbox" android:text="@string/interest_foodAndBeverage" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbFashion" style="@style/joyship_control.checkbox" android:text="@string/interest_fashion" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbPolitics" style="@style/joyship_control.checkbox" android:text="@string/interest_politics" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbBusiness" style="@style/joyship_control.checkbox" android:text="@string/interest_business" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbTechnology" style="@style/joyship_control.checkbox" android:text="@string/interest_technology" /> <android.support.v7.widget.AppCompatCheckBox android:id="@+id/cbScience" style="@style/joyship_control.checkbox" android:layout_marginBottom="@dimen/halfMainMargin" android:text="@string/interest_science" /> </android.support.v7.widget.LinearLayoutCompat> </android.support.constraint.ConstraintLayout> <style name="joyship_control"> <item name="android:layout_width">match_parent</item> <item name="android:layout_marginStart">@dimen/marginMainPlusShadow</item> <item name="android:layout_marginEnd">@dimen/marginMainPlusShadow</item> <item name="android:fontFamily">@font/josefin_sans_regular</item> <item name="android:gravity">center_vertical</item> <item name="android:textColor">@color/colorText</item> <item name="android:textSize">@dimen/fontSizeM</item> </style> <style name="joyship_control.checkbox" parent="joyship_control"> <item name="android:layout_height">@dimen/controllerHeight</item> <item name="android:background">@null</item> <item name="android:button">@null</item> <item name="android:drawableEnd">@drawable/cb_joyship</item> </style> 结合使用:

GROUP BY

以上查询按出价汇总,然后仅保留那些出现一次的出价(LIMIT)。然后,它按买入价升序排列,并且仅保留一行,该行是最低价。