Recent questions tagged MySQL

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Is there any way to store mysql result in php variable? thanks $query = "SELECT username,userid FROM user ... print selected userid from query. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - How would I use ON DUPLICATE KEY UPDATE in my CodeIgniter model?

I have a CodeIgniter/PHP Model and I want to insert some data into the database. However, I have this ... ActiveRecord-based model? Thanks! Jack See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql date comparison with date_format

I googled and tried several ways to compare date but unfortunately didn't get the result as expected. I have ... suggestion? Thanks in advance. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - How to convert ISO8601 to Date format in php

How to convert this (in ISO8601 format): 2014-03-13T09:05:50.240Z To this (in MySQL DATE format): 2014-03-13 in php? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - SQL query with avg and group by

I have some problems with writing a SQL query for MySQL. I have a table with the following structure: mysql> ... specific 'id'. Any ideas? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - Composite key as foreign key (sql)

here are my two tables of concern: CREATE TABLE IF NOT EXISTS `tutorial` ( `beggingTime` time NOT NULL, `day ... each primary key in 'tutorial'? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - libmysqlclient15-dev on macs?

Does OSX need an install of libmysqlclient15-dev? I'm trying to compile a gem that is failing and a lot of ... . Am I missing something here? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - How to pass a variable to a IN clause?

Lets say I have a SP that has a SELECT statements as follows, SELECT product_id, product_price FROM product WHERE ... idea how to do this? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - SELECT INTO and "Undeclared variable" error

When I try to execute following query: SELECT id_subscriber INTO newsletter_to_send FROM subscribers I get an error: ... with that query ? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - Python Pandas write to sql with NaN values

I'm trying to read a few hundred tables from ascii and then write them to mySQL. It seems easy to ... suggestions would be greatly appreciated. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - WHERE datetime older than some time (eg. 15 minutes)

I was looking at: MySQL Select rows where timestamp column between now and 10 minutes ago I have a col ... minutes present in the database. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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389 views

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mysql - Sorting string column containing numbers in SQL?

I am trying to sort string column (containing numbers). // SELECT `name` FROM `mytable` ORDER BY `name` ... result-set at application level? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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638 views

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mysql - How to force case sensitive table names?

I'm working on a MySQL database in windows. I must move it into a Linux environment. MySQL database ... sensitive table names in windows? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - Laravel join with 3 Tables

I am building a Twitter-like app. There is a Feed in which I want to only show posts of Users who I follow ... work. Any help is appreciated :) See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - SQL search multiple values in same field

I'm building a simple search algorithm and I want to break my string with spaces, and search my database on it, ... ]% LIMIT 6 Is this possible? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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444 views

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mysql - How do I count columns of a table

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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469 views

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mysql - Case Expression vs Case Statement

What is the difference between a Case Expression and a Case Statement in MySQL? When can they be used, and what ... they seem to be identical? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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658 views

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mysql - Field 'id' doesn't have a default value?

I am new to this SQL; I have seen similar question with much bigger programs, which I can't understand at the moment ... , 'vantar', 'vantar' ); See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - Data truncated for column?

After changing the data type of a MySql column in order to store Twilio call ids (34 char strings), I try ... column 'incoming_Cid' at row 1 See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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756 views

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mysql - Hamming distance on binary strings in SQL

I have a table in my DB where I store SHA256 hashes in a BINARY(32) column. I'm looking for a way to ... See the comments to my answer below. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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457 views

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mysql - Meaning of "n:m" and "1:n" in database design

In database design what do n:m and 1:n mean? Does it have anything to do with keys or relationships? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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472 views

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mysql - Returning a value even if no result

I have this kind of simple query that returns a not null integer field for a given id: SELECT ... method SimpleJdbcTemplate.queryForLong()). See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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715 views

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mysql - "SELECT COUNT(*)" is slow, even with where clause

I'm trying to figure out how to optimize a very slow query in MySQL (I didn't design this): SELECT ... but there's no performance difference). See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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688 views

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mysql - Is there any performance gain in indexing a boolean field?

I'm just about to write a query that includes a WHERE isok=1. As the name implies, isok is a boolean field ... or worse looking up the index? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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696 views

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mysql 如何搜索10个条件里面满足两个及以上的行？

有一个tag表: id tag 1 a,b,c 2 a,c,d 3 a 4 e,g,z 5 a,y,z 请问如何查询 tag 里满足包含[a,c,e,f,g] 里面任意两个以上的？也就是匹配到a,c的第一行第二行，匹配到e,g的第四行...

asked Jan 29, 2021 in Technique[技术] by 深蓝 (71.8m points)

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626 views

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mysql - Update column with value from another column

In a SQL table I have two columns: the first contain a path and the second contains a value. colunm1 /path/ colunm2 12345...

asked Jan 29, 2021 in Technique[技术] by 深蓝 (71.8m points)

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430 views

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mysql 如何匹配多个 like 条件?

有一个tag表: id tag 1 a,b,c 2 a,c,d 3 a 请问如何查询 tag 里包含 a 和 c 的？也就是第一行和第二行...

asked Jan 29, 2021 in Technique[技术] by 深蓝 (71.8m points)

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