Cov txheej txheem:

Dab tsi yog qhov qhia hauv Microsoft Access?
Dab tsi yog qhov qhia hauv Microsoft Access?

Video: Dab tsi yog qhov qhia hauv Microsoft Access?

Video: Dab tsi yog qhov qhia hauv Microsoft Access?
Video: Xwm Kab Yog Dab Tsi?: Hmoob Nkag Siab Yuam Kev Tag Lawm 2024, Kaum ib hlis
Anonim

Ib kev qhia yog ib qho kev sib xyaw ua ke ntawm cov lej lossis cov tswv yim kev xav, qhov tsis tu ncua, kev ua haujlwm, cov lus teb, kev tswj hwm, thiab cov khoom uas ntsuas rau ib tus nqi. Koj siv tau cov lus qhia hauv Nkag mus xam cov nqi, validate cov ntaub ntawv, thiab teem ib tug default value.

Ib yam li ntawd, koj siv cov kab lus hauv kev nkag mus li cas?

Siv cov lus qhia raws li cov lus nug

  1. Hauv Navigation Pane, right-click the query that you want to change, and then click Design View on the shortcut menu.
  2. Nyem rau hauv Cov Txheej Txheem Cell hauv kab uas koj xav nkag mus rau koj cov txheej txheem.
  3. Txhawm rau tsim koj cov lus qhia manually, ntaus koj cov qauv qhia.

Qhov thib ob, qhov exclamation mark txhais li cas hauv cov lus nug nkag? Siv Cov ntsiab lus exclamation thiab Lub Sijhawm. Siv ib exclamation point ua ntej lub npe thaum lub npe hais txog ib yam khoom uas nyob rau hauv cov khoom ua ntej los yog sau cov khoom. Ib lub npe tom qab ib exclamation point feem ntau yog lub npe ntawm cov khoom koj tsim (xws li daim ntawv lossis lub rooj).

Kuj nug, ua li cas koj tsim cov lus nug hloov tshiab?

Kauj ruam 1: Tsim cov lus nug xaiv los txheeb xyuas cov ntaub ntawv hloov tshiab

  1. Qhib lub database uas muaj cov ntaub ntawv koj xav hloov tshiab.
  2. Ntawm Cov Tsim tab, hauv Cov Lus Nug Pab Pawg, nyem Query Design.
  3. Nyem qhov Tables tab.
  4. Xaiv lub rooj lossis cov rooj uas muaj cov ntaub ntawv uas koj xav hloov tshiab, nyem Ntxiv, thiab tom qab ntawd nyem Kaw.

Dab tsi tsis yog null access expression?

MS Access IsNull () Function Cov IsNull () muaj nuj nqi xyuas seb ib qho kev qhia muaj Null ( tsis muaj cov ntaub ntawv). Txoj haujlwm no rov qab tus nqi Boolean. TRUE (-1) qhia tias tus kev qhia yog a Null tus nqi, thiab FALSE (0) qhia tias qhov qhia tsis yog a Null tus nqi.

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