sql tag

625 questions

1 answers
386 views
0

If the reference value is NULL when creating the View table, I want to merge under different conditions.

We are currently creating a View table.I am combining the table data as shown below, but if hoge2.player1_id is NULL, I would like to combine the player table with hoge.player1_id.CREATE VIEWHOGE_view...

mysql sql

2 years ago

1 answers
436 views
0

If I change the MySQL isolation level for each transaction, what is the load on the DB?

I'm using TypeORM as the ORM for Node.js, but when I look at the document (https://typeorm.io/#/transactions),import {getManager} from typeorm;wait getManager().transaction(SERIALIZABLE, transactional...

mysql node.js

2 years ago

1 answers
505 views
0

What happens if I set the transaction isolation level arbitrarily in the source code?

As for how to set the transaction isolation level, Spring can be set casually by adding @Transactional for each method, or Rails can be set casually by ApplicationRecord.transaction (isolation:read_co...

ruby-on-rails sql database spring

2 years ago

2 answers
72 views
0

If mysql sets the external connection to root@%, it cannot be created.

If you set mysql to externally connectable root@%, you will not be able to createGRANT ALL PRIVILEGES ON shop.shop TO root@'%' Authorization GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD,...

mysql

2 years ago

1 answers
88 views
0

I don't want to write the same query over and over again because the query is redundant.

Yes, it is possible to do it as it is, but I was wondering what to do to avoid redundancy, so I asked you.I tried my_goals - enemy_goals but now it's Unknown columns.The original SQL is the correct pa...

mysql sql

2 years ago

1 answers
96 views
0

Couldn't find User without an ID Error

Couldn't find User without an ID error appears in the code below.def index @user=User.find (params[:id]) sort_key=(params[:column].blank?||params[:order].blank?)?{updated_at:'DESC'}:{params[:column]=&...

ruby-on-rails ruby sql

2 years ago

2 answers
85 views
0

SQL Grouping Continuous Values in Time Series Data

I,T,VA, 10A, 20A, 3, 1A, 4, 1A, 5, 1A, 6,0A, 7, 1A, 8, 1A, 9,0A,10,0How do I generate the following data in SQL when I have this data?

sql

2 years ago

1 answers
128 views
0

I want to run a schema-specified query without writing the schema name in the query.

ASK: 　Is there a way to do the following without writing the schema name in the query?Environment: postgreSQL 9.x Windows If possible, I'd like to run it on pgAdmin4 (Because I'm not used to running f...

sql postgresql

2 years ago

1 answers
172 views
0

In order to migrate the POSGRE database to AWS dynamicb, we would like to extract it in json format first.

In order to migrate the POSGRE database to AWS dynamicb, we would like to extract it in json format first.Therefore, we have considered the following statements to range multiple tables and output sel...

json postgresql amazon-dynamodb

2 years ago

1 answers
132 views
0

'Illegal mix of collations' Error Occurs When Running Mysqldump

Attempting to dump an existing database in MySQL on a Windows PC mysqldump-uroot-p testdb>testdb.dumpWhen I ran , the following error occurred:mysqldump Error: 'Illegal mix of collations (utf8_gene...

mysql

2 years ago

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