Cov txheej txheem:
Video: Kuv yuav ua li cas kom kuv SQL code ua haujlwm zoo dua?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Hauv qab no yog 23 txoj cai los ua kom koj SQL sai thiab ua haujlwm tau zoo
- Batch cov ntaub ntawv tshem tawm thiab hloov tshiab.
- Siv tsis siv neeg muab faib SQL ntawv server nta.
- Hloov scalar functions rau hauv cov lus muaj nuj nqis.
- Hloov kho tshiab, siv CASE.
- Txo cov nested views kom txo lags.
- Cov ntaub ntawv pre-staging.
- Siv cov ntxhuav temp.
- Tsis txhob siv rov siv dua code .
Tsis tas li ntawd, kuv tuaj yeem txhim kho kuv cov ntaub ntawv kev ua tau zoo li cas?
5 Txoj Kev Yooj Yim Los Txhim Kho Koj Cov Ntaub Ntawv Kev Ua Haujlwm
- Optimize Cov Lus Nug. Feem ntau, cov teeb meem kev ua tau zoo yog tshwm sim los ntawm kev ua haujlwm tsis zoo ntawm SQL queries.
- Tsim cov indexes zoo.
- Tau txais CPU muaj zog dua.
- Muab lub cim xeeb ntxiv.
- Cov ntaub ntawv defragmentation.
- Hom Disk.
- Database version.
Tsis tas li ntawd, kuv yuav ua li cas kom MySQL cov lus nug khiav nrawm dua? Cia peb saib cov lus qhia tseem ceeb tshaj plaws thiab muaj txiaj ntsig los txhim kho MySQL Query kom nrawm thiab ua haujlwm.
- Optimize koj Database.
- Optimize Koom.
- Index Txhua Kab Siv nyob rau hauv 'qhov twg', 'order by', thiab 'pab pawg los ntawm' Clauses.
- Siv Cov Ntawv Sau Tag Nrho.
- Ua kom zoo ib yam li nqe lus nrog Union Clause.
- MySQL Query Caching.
Kuj kom paub, dab tsi yog txoj hauv kev sib txawv los txhim kho SQL query?
Nws yog ib qho tseem ceeb uas koj ua kom zoo dua koj cov lus nug rau qhov cuam tshuam tsawg kawg nkaus ntawm kev ua haujlwm database
- Txhais kev ua lag luam ua ntej.
- SELECT teb es tsis txhob siv SELECT *
- Tsis txhob SELECT DISTINCT.
- Tsim kev koom nrog INNER JOIN (tsis yog qhov twg)
- Siv qhov twg los ntawm HAVING los txhais cov ntxaij lim dej.
- Siv wildcards tom kawg ntawm ib kab lus nkaus xwb.
Qhov kev koom nrog yog nrawm dua hauv SQL?
Zoo, feem ntau PIB HAIV NEEG yuav sai dua vim tias nws tsuas yog rov qab cov kab sib tw hauv txhua lub rooj sib koom ua ke raws li cov kab sib koom. Tab sis LEFT JOIN yuav rov qab tag nrho cov kab los ntawm cov lus teev tseg LEFT thiab tag nrho cov kab sib txuam los ntawm lub rooj teev tseg RIGHT.
Pom zoo:
Kuv yuav ua li cas kom kuv lub laptop tshiab kom zoo?
Siv koj lub laptop hauv cov xwm txheej zoo. Xyuas kom koj txhais tes huv si ua ntej siv koj lub laptop. Muab koj lub laptop tso rau ntawm qhov chaw huv, tsis muaj plua plav. Xyuas kom lub laptop zoo-ventilated los ntawm kev xyuas kom meej tias cov vents ntshiab ntawm kev thaiv. Khaws koj ib puag ncig ntawm qhov nruab nrab kub
Kuv puas yuav tau lub koob yees duab zoo dua lossis lub lens zoo dua?
Hauv kuv lub tswv yim, hais txog kev nqis peev nyiaj txiag, lub goodlens yog qhov kev xaiv zoo dua vim tias nws yuav kav koj ntev dua li lub cev (raws li koj feem ntau yuav hloov lub koob yees duab sai dua li cov lo ntsiab muag). Tib lo ntsiab muag, ntawm qhov tod tes, yuav zoo li tseem siv tau tsib mus rau 10 xyoo txij li tam sim no (yog tias tsis ntev dua)
Nws txhais li cas rau kev ua haujlwm kom rov ua haujlwm dua?
Ib txoj haujlwm yog rov ua dua yog tias nws tuaj yeem raug hu thaum twb nyob rau hauv tus txheej txheem ntawm kev ua. Ntawd yog, kev ua haujlwm yog rov ua dua yog tias nws tuaj yeem cuam tshuam hauv nruab nrab ntawm kev ua tiav (piv txwv li, los ntawm lub teeb liab lossis cuam tshuam) thiab rov hais dua ua ntej kev cuam tshuam kev ua tiav
Kuv yuav ua li cas kom kuv qhov kev sib txuas hauv Is Taws Nem kom zoo?
Ntu 1 Xyuas Koj Cov Kho vajtse, Network thiab kev sib txuas Khiav ib qho kev xeem ceev. Sib piv koj cov txiaj ntsig tawm tsam qhov koj tau them rau. Reset koj modem. Tshawb nrhiav qhov chaw cuam tshuam. Tshawb xyuas seb koj puas tau mus txog lub peev xwm ntawm cov ntaub ntawv. Hu rau koj tus kws kho mob hauv internet. Xyuas tag nrho cov khoom siv hauv koj lub network
Yuav ua li cas koj nce Windows 10 kev ua tau zoo thiab ua kom nws zoo dua?
Windows 10 Operating System Ceev Tweaks Qhib Hom Game. Tua tawm Visual Effects. Ua kom koj lub processor ceev. Tua tawm Auto-Starting Programs. Tshawb xyuas koj qhov kev sib txuas hauv Is Taws Nem. Tswj Windows Update rau Kev Ua Haujlwm. Tua Windows 10's Search IndexingFeature. Storage Analyzers thiab Disk Cleaning tuaj yeem ua kom nrawm rau Windows