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- MariaDB 10.3.7 is the first GA release
https://mariadb.com/kb/en/library/mariadb-1037-release-notes/
- MariaDB 10.3 translates `LENGTH()` to `OCTET_LENGTH()` function
https://mariadb.com/kb/en/library/sql_modeoracle-from-mariadb-103/
> MariaDB translates LENGTH() to OCTET_LENGTH()
- MySQL does NOT translate `LENGTH()` to `OCTET_LENGTH()`
However, it translates `OCTET_LENGTH()` to `LENGTH()`
Here are generated schema dumps of this test to show the differences
between MySQL and MariaDB:
* MySQL 8.0 (Server version: 8.0.11 MySQL Community Server - GPL)
```ruby
create_table \"virtual_columns\", options: \"ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci\", force: :cascade do |t|
t.string \"name\"
t.virtual \"upper_name\", type: :string, as: \"upper(`name`)\"
t.virtual \"name_length\", type: :integer, as: \"length(`name`)\", stored: true
t.virtual \"name_octet_length\", type: :integer, as: \"length(`name`)\", stored: true
end
```
* Maria DB 10.3 (Server version: 10.3.7-MariaDB-1:10.3.7+maria~bionic-log mariadb.org binary distribution)
```ruby
create_table \"virtual_columns\", options: \"ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci\", force: :cascade do |t|
t.string \"name\"
t.virtual \"upper_name\", type: :string, as: \"ucase(`name`)\"
t.virtual \"name_length\", type: :integer, as: \"octet_length(`name`)\", stored: true
t.virtual \"name_octet_length\", type: :integer, as: \"octet_length(`name`)\", stored: true
end
```
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MySQL generated columns: https://dev.mysql.com/doc/refman/5.7/en/create-table-generated-columns.html
MariaDB virtual columns: https://mariadb.com/kb/en/mariadb/virtual-computed-columns/
Declare virtual columns with `t.virtual name, type: …, as: "expression"`.
Pass `stored: true` to persist the generated value (false by default).
Example:
create_table :generated_columns do |t|
t.string :name
t.virtual :upper_name, type: :string, as: "UPPER(name)"
t.virtual :name_length, type: :integer, as: "LENGTH(name)", stored: true
t.index :name_length # May be indexed, too!
end
Closes #22589
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