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mysql 給表字段設(shè)置默認(rèn)值的好處？怎么去設(shè)置默認(rèn)值

mysql 給表字段設(shè)置默認(rèn)值的好處？怎么去設(shè)置默認(rèn)值

From [MySQLdiscussion group] 2017-04-17 11:57:46 0  1  2046

php - 數(shù)據(jù)庫(kù)存圖片，是存圖片名稱？還是存圖片路徑？？

數(shù)據(jù)庫(kù)存圖片，是存圖片名稱？還是存圖片路徑？？ 問(wèn)題如上，之所以會(huì)有這么個(gè)疑問(wèn)，目前圖片是在本地服務(wù)器上存的，但是以后若是業(yè)務(wù)規(guī)模擴(kuò)大，那圖片肯定是要遷移到云存儲(chǔ)服務(wù)上的，那個(gè)時(shí)候圖片路徑會(huì)改動(dòng)，我...

From [MySQLdiscussion group] 2017-04-17 16:52:36 0  6  2040

Why is there no sound?

Why is there no sound?

From [MySQLdiscussion group] 2019-07-01 19:59:33 0  1  2038

CommandText property initialization problem

I'm trying to materialize data into 2 (later 3) tables simultaneously using a C# console application. I want t...

From [MySQLdiscussion group] 2024-04-04 22:43:24 0  1  2012

mysql - efficiency issues of inner join and left join

Under what circumstances will the execution efficiency of inner join and left join be relatively high?

From [MySQLdiscussion group] 2017-06-24 09:41:36 0  2  2009

How to solve the problem of "ORA-00922: missing or invalid option" error?

I entered the following SQL command in Oracle, but it reported the error "ORA-00922: Option missing or in...

From [MySQLdiscussion group] 2023-08-22 18:45:24 0  2  1995

mysql在限制條件下篩選某列數(shù)據(jù)相同的值？

有一個(gè)schema如下fish（name,species,tankid） eat(species1，species2)其中eat表示魚類之間相互捕食關(guān)系，species1是被捕食的魚類tankid表示魚缸id需要篩選出：...

From [MySQLdiscussion group] 2017-03-23 09:18:11 0  2  1993

There is no output result and no error message.

It seems that I encountered the same problem as above? Tested in PHPstudy, the information is as follows. I ch...

From [MySQLdiscussion group] 2018-04-15 15:56:54 0  5  1990

sql語(yǔ)句中 values值為什么要加單引號(hào)呢？

sql語(yǔ)句中 values值為什么要加單引號(hào)呢？values里面的放的本身就是PHP變量名字呀，雙引號(hào)中可以解析變量值，為什么還要在變量中加單引號(hào)呢

From [MySQLdiscussion group] 2016-12-20 16:53:03 0  2  1965

In the multibyte target code page, there is no map to which this Unicode character can...

The content has a lot of text. After running it in the SQL editor, it looks like this. How can I solve it?

From [MySQLdiscussion group] 2017-11-10 11:18:27 0  0  1950

mysql - 數(shù)據(jù)庫(kù)插入頻繁導(dǎo)致數(shù)據(jù)丟失

插入語(yǔ)句有兩條，循環(huán)插入這兩條只是簡(jiǎn)單寫了下插入語(yǔ)句，沒(méi)有捕捉到異常 {代碼...} 查看數(shù)據(jù)庫(kù)時(shí)，發(fā)現(xiàn)少了很多，我猜應(yīng)該是頻繁插入導(dǎo)致數(shù)據(jù)丟失的，因?yàn)槲以诓迦霐?shù)據(jù)庫(kù)之前把數(shù)據(jù)print了一下，沒(méi)少。怎么解決...

From [MySQLdiscussion group] 2017-04-17 15:14:37 0  4  1939

mysql - How to set the group by statement in sequel Pro to default to the first record of the group

select age,money from t1.gz group by age;發(fā)現(xiàn)報(bào)錯(cuò)：Expression #2 of SELECT list is not in GROUP BY clause and conta...

From [MySQLdiscussion group] 2017-07-07 10:35:36 0  1  1937

mysql日期類型默認(rèn)值'0000-00-00' 報(bào)錯(cuò)，是什么問(wèn)題？

如題，本來(lái)是 從另一個(gè)數(shù)據(jù)庫(kù)中導(dǎo)出的sql文件，在我電腦上導(dǎo)入報(bào)這個(gè)錯(cuò)誤，不知道是不是mysql 版本問(wèn)題。多方搜索無(wú)果，所以上來(lái)求助。DROP TABLE IF EXISTS `...

From [MySQLdiscussion group] 2017-03-16 09:11:32 0  2  1926

mysql - After messing around with PHPMyadmin came up - #2002 - - The server is not responding (or the local server's socket is not set up correctly).

Because I need a computer on the LAN to remotely access my phpmyadmin, I need to open a remote connection. So ...

From [MySQLdiscussion group] 2017-05-27 17:39:15 0  2  1898

mysql - 如何在數(shù)據(jù)庫(kù)里優(yōu)化 漢明距離 查詢？

項(xiàng)目里需要一個(gè)搜索相似圖片的功能，百度了一些dhash的算法，生成了16個(gè)長(zhǎng)度的hash值，在mysql里這樣查詢： {代碼...} 經(jīng)測(cè)試，15W條數(shù)據(jù)，搜索需要很長(zhǎng)時(shí)間。第二次速度會(huì)快些，有啥辦法可以優(yōu)化？

From [MySQLdiscussion group] 2017-04-17 14:54:25 0  2  1897