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Rewrite the title as: How to convert data type of "unnamed 0" column of pandas dataframe from int64 to string or object

I'm working on a small project trying to send a dataframe from pandas to a mysql database. My dataframe contai...

From [MySQLdiscussion group] 2023-09-04 20:00:13 0  1  759

MySQL Pivot Table Query: Using Dynamic Columns for Data Analysis

I'm using the following table to store product data: mysql>SELECT*FROMproduct;+---------------+--------...

From [MySQLdiscussion group] 2023-08-22 11:54:19 0  2  759

When using EF Core to query MySQL in C#, the primary key column name is incorrect

I'm learning how to query a Mysql database in C# but I'm getting an error saying there is an invalid column in...

From [MySQLdiscussion group] 2023-08-17 13:45:14 0  1  759

Count the number of Laravel and Mysql related models through intermediate tables using additional conditions.

I have a MySQL query built using Laravel Eloquent's eager loading and withCount functions, but I have some per...

From [MySQLdiscussion group] 2023-07-24 15:47:02 0  1  759

Should the length of varchar type in MySQL be a multiple of the field's encoding?

I once saw someone on stackoverflow saying that it is recommended that when the length of the varchar field ca...

From [MySQLdiscussion group] 2017-05-18 10:49:34 0  3  759

MYSQL query to copy all data in a column from one database to another

I accidentally used the "Generate Description" feature on the Opencart SEO tool and it overwrote all...

From [MySQLdiscussion group] 2024-04-01 00:00:37 0  1  758

How to distribute duplicate rows in MySQL output?

I have a MySQL query that outputs rows in random order. Each row has a name column, and sometimes queries may ...

From [MySQLdiscussion group] 2023-09-13 15:45:37 0  1  758

How to calculate the difference between two SQL queries

I want to do subtraction between entotalitem and exotalitem, the query I am using is to retrieve data from the...

From [MySQLdiscussion group] 2023-09-07 20:06:33 0  1  758

node.js - 抽獎碼設(shè)計(jì)問題

程序的邏輯： 程序事先生成了抽獎碼存在mysql中，然后有用戶來的以后，找到一個(gè)沒有用過的抽獎碼給他，然后把這個(gè)抽獎碼設(shè)置成為已經(jīng)使用過了 問題：當(dāng)大量用戶同時(shí)并發(fā)請求的時(shí)候，大部分用戶返回同一個(gè)抽獎碼 ...

From [MySQLdiscussion group] 2017-04-17 15:17:18 0  3  758

字符編碼 - 關(guān)于 MySQL 的 varchar 長度計(jì)算的疑問

先創(chuàng)建一個(gè)表 {代碼...} 字段a類型為varchar，長度3為三個(gè)字節(jié)，也就是說字段a里面最多可以存三個(gè)字節(jié)長度的數(shù)據(jù)。 但是我只想下面的sql語句竟然能成功。SQL語句為: {代碼...} “漢”unicode的字...

From [MySQLdiscussion group] 2017-04-17 11:56:39 0  7  758

mysql - sql字段包含逗號

我做數(shù)據(jù)庫插入時(shí)，碰到插入字段有逗號。執(zhí)行提示語法錯(cuò)誤，這個(gè)應(yīng)該怎樣處理？？ 其中某一條： 。。。(word , pos , from) VALUES ('word','noun,verb','word')'

From [MySQLdiscussion group] 2017-04-17 11:51:13 0  2  758

How to import a MySQL database from the terminal?

How to import mysql database from terminal? I can't find the exact syntax.

From [MySQLdiscussion group] 2023-10-10 11:36:13 0  2  757

mysql - 觸發(fā)器的實(shí)際使用場景, 可能也就是這個(gè)了, 一起討論還有沒有別的

觸發(fā)器的實(shí)際使用場景大體說來就是幫你方便的遷移數(shù)據(jù), 不過最好不要和業(yè)務(wù)緊密結(jié)合, 因?yàn)橐粋€(gè)事務(wù)的的一部分在java那邊, 另另一部分在觸發(fā)器中是無法很方便的調(diào)試/排查/維護(hù)的, 唯有一個(gè)場景, 就是不想物理刪數(shù)...

From [MySQLdiscussion group] 2017-04-17 16:40:51 0  2  757

mysql - windows手動安裝php5.7.17，啟動失敗

windows手動安裝php5.7.17，啟動失敗.也intialize（初始化）過,沒報(bào)錯(cuò) 啟動不了： 求解！

From [MySQLdiscussion group] 2017-04-17 16:30:42 0  0  757

mysql 的IFNULL失效

想要判斷當(dāng)查找的值找不到時(shí)給一個(gè)默認(rèn)值，就試試IFNULL函數(shù)。這樣是可以查到的select IFNULL(NULL,'null') as name from game 輸出結(jié)果： 但是當(dāng)加了查詢套件卻出不來了： {代碼...

From [MySQLdiscussion group] 2017-04-17 15:50:46 0  1  757