Recent questions tagged MySQL

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mysql - Storing day and month (without year)

I'm having trouble with figuring out the best way to store some data in my database. I've got to store DD/ ... this almost doesn't seem right. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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778 views

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mysql - Multiple inner joins with multiple tables

So I have four tables. Each table has a single id for the previous table id. So my in click table has an id ... solution that i'm not aware of. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - How to define unique index on multiple columns in sequelize

How do I define a unique index on a combination of columns in sequelize. For example I want to add a unique ... .STRING, allowNull: true, }) See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - Create an inline SQL table on the fly (for an excluding left join)

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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575 views

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mysql - how to check if a string looks randomized, or human generated and pronouncable?

For the purpose of identifying [possible] bot-generated usernames. Suppose you have a username like "bilbomoothof ... /MySQL most appreciated. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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859 views

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mysql - How to add AUTO_INCREMENT to an existing column?

How do I add auto_increment to an existing column of a MySQL table? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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575 views

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mysql - Is it OK to query a MongoDB multiple times per request?

Coming from an RDBMS background, I was always under the impression "Try as hard as you can to use one query, ... Is that bad practice in NoSQL? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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640 views

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mysql - When should I use transactions in my queries?

I'm reading very detailed tutorials on how to use transactions with database types and database engines, but I ... t worry about that? thanks See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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717 views

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mysql - Creating tables and problems with primary key in Rails

When I try to run the following code in Rails using Mysql2 as database manager: rake db:migrate I obtain the ... " t.timestamps end end end See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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mysql - SQLSTATE[42000]: Syntax error or access violation: 1055 Expression #3 of SELECT list is not in GROUP BY clause and contains nonaggregated

when i got upgraded my ubuntu from 15.10 to 16.04 i have this erro in my yii2 project SQLSTATE[42000]: Syntax ... DESC how to solve my problem ? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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817 views

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mysql - CAST DECIMAL to INT

I'm trying to do this: SELECT CAST(columnName AS INT), moreColumns, etc FROM myTable WHERE ... I've looked at the ... is 223.00 and I want 223 See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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657 views

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mysql - What is a good database design (schema) for a attendance database?

I'm trying to make a application for keeping attendance for a relative's martial arts studio. I've tried ... of database? Thanks in advance. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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652 views

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mysql - How do I create a Django model with ForeignKeys which does not cascade deletes to its children?

One of my models which has ForeignKey's is actually a MySQL view on other tables. The problem I'm running ... view instead of raising an error? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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875 views

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mysql - Rails: Force empty string to NULL in the database

Is there an easy way (i.e. a configuration) to force ActiveRecord to save empty strings as NULL in the DB (if ... s a way to do this already. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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837 views

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mysql - Group by day from timestamp

In my posts table, it saves timestamp for each post record. What query can group posts by day, using this timestamp column? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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838 views

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mysql - mysqldump with create database line

I'm in the process of moving my files onto another computer, and one thing I would like to do is to transfer the ... Is there a way to do that? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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834 views

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mysql - Creating an index on a timestamp to optimize query

I have a query of the following form: SELECT * FROM MyTable WHERE Timestamp > [SomeTime] AND Timestamp < [ ... me to optimize this query? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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707 views

1 answer

mysql - Best way to handle storing/displaying dates in different timezones in PHP?

I've been reading up on this topic for the past few hours, and I think I've got a handle on it, but ... a better solution? Thanks for your help! See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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685 views

1 answer

mysql - WHERE statement after a UNION in SQL?

How do I apply a WHERE statement after a UNION in SQL/MySQL? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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976 views

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mysql - How to update column with null value

I am using mysql and need to update a column with a null value. I have tried this many different ways and the ... a special syntax to do this? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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709 views

1 answer

mysql - How To Avoid Repair With Keycache?

I have had some experience with optimizing the my.cnf file but my database has around 4 million records ... set-variable = thread_concurrency=8 See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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974 views

1 answer

mysql - How to select count with Laravel's fluent query builder?

Here is my query using fluent query builder. $query = DB::table('category_issue') ->select('issues.*') - ... be appreciated, thanks in advance! See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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711 views

1 answer

mysql - Populate PHP Array from While Loop

If I am fetching data from a MySQL database and using a while loop to iterate through the data how would I ... = mysql_fetch_assoc($result)) { } See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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720 views

1 answer

mysql - What's better - many small tables or one big table?

I've got a database which will store profiles about individuals. These individuals have about 50 possible fields. Some ... what I am doing? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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742 views

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mysql - RuntimeError with mysql2 and rails3 (bundler)

I get this error `establish_connection': Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` ... my config and gemfile. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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694 views

1 answer

mysql - Order SQL by strongest LIKE?

I have the following query: SELECT * FROM table_name WHERE (col_1 LIKE '%$keyword%' OR col_2 LIKE '%$keyword%' ... on the most relevant results? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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1.0k views

1 answer

mysql - "Data too long for column" - why?

I've written a MySQL script to create a database for hypothetical hospital records and populate it with data. ... . Anyone have some insight? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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737 views

1 answer

mysql - How many characters can you store with 1 byte?

1 byte = 8 bits So, does this mean 1 byte can only hold one character? E.g.: "16" uses 2 bytes , "9" uses ... (2) what will be the range 0-10 See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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