Tsis muaj hom ntaub ntawv boolean ib txwmrau SQLite. Raws li Datatypes doc: SQLite tsis muaj chav kawm Boolean cais. Hloov chaw, Boolean qhov tseem ceeb yog khaws cia ua tus lej 0 (tsis tseeb) thiab 1 (tseeb).
Koj pom cov ntaub ntawv boolean li cas?
Nrog JavaScript dawb huv, koj tsuas yog siv tau typeof thiab ua qee yam xws li hom cuav lossis hom tseeb thiab nws yuav rov qab "boolean" … const isBoolean=val=> 'boolean '===typeof val; thiab hu nws zoo li!
Koj tshaj tawm li cas boolean hauv SQL?
Koj tuaj yeem ntxig tus nqi boolean siv cov lus INSERT: INSERT INTO testbool (sometext, is_checked) VALUES ('a', TRUE); INSERT INTO testbool (sometext, is_checked) VALUES ('b', FALSE); Thaum koj xaiv tus nqi boolean, nws tshwm sim li 't' lossis 'f'.
Puas muaj cov ntaub ntawv boolean hauv SQL?
Muaj boolean cov ntaub ntawv hom hauv SQL Server. Nws qhov txiaj ntsig tuaj yeem yog TRUE, FALSE lossis UNKNOWN. Txawm li cas los xij, hom ntaub ntawv boolean tsuas yog qhov tshwm sim ntawm boolean qhia uas muaj qee qhov sib xyaw ua ke ntawm cov neeg ua haujlwm sib piv (piv txwv li=,,=) lossis cov tswv lag luam (piv txwv li THIAB, LOSSIS, IN, EXISTS).
Puas Boolean muaj lossis tsis yog?
Los ntawm lub rooj sib tham, peb siv hom BOOL rau Boolean tsis, cov khoom, thiab cov piv txwv sib txawv thiab siv YES thiab TSIS MUAJthaum sawv cev qhov tseem ceeb ntawm Boolean. Vim tias NULL thiab nil xoom qhov tseem ceeb, lawv ntsuas rau "tsis tseeb" hauv cov lus qhia.
