issues-179 Add support for view

[ikrivosheev]

PR Info

• Closes Please add support for views #179

Depends on:

• issues-347 Add SqlWriter trait #436

Adds

Add support for: create, delete, rename VIEW.

TODO:

• add backends
• add tests
• add docs

[ikrivosheev]

I need more time for support backends, because SQLite, MySQL and Postgres are very different in the details.

[ikrivosheev]

@tyt2y3 @billy1624, hello. POC for support VIEW is done (without docs and tests). I have one question: ViewCreateStatement has field: query which is SelectStatement. For transform SelectStatement to SQL needed impl QueryStatementBuilder on the other hand: ViewDropStatement does not needed QueryStatementBuilder (only SchemaStatementBuilder).

What to do? In impl ViewStatement everywhere return (String, Values) or is there something better?

[ikrivosheev]

@tyt2y3 @billy1624 any ideas?

[billy1624]

Hey @ikrivosheev, sorry for the delay. What a huge PR loll

Notice a few things. For, create view:

• OR REPLACE is supported by MySQL, MariaDB and PostgreSQL, SQLite wasn't supported
• However, IF NOT EXISTS is supported by SQLite but not the other three db
• TEMPORARY is supported by PostgreSQL and SQLite but not the other two db
• RECURSIVE is supported only by PostgreSQL
• WITH [ CASCADED | LOCAL ]...

And, the list goes on. I think it's better to document these db specific features later in this PR. Or, even, dump some of the feature that supported by only one db.

References:

• https://dev.mysql.com/doc/refman/8.0/en/create-view.html
• https://mariadb.com/kb/en/create-view/
• https://www.postgresql.org/docs/current/sql-createview.html
• https://www.sqlite.org/lang_createview.html

[ikrivosheev]

Hey @ikrivosheev, sorry for the delay. What a huge PR loll

Notice a few things. For, create view:

• OR REPLACE is supported by MySQL, MariaDB and PostgreSQL, SQLite wasn't supported
• However, IF NOT EXISTS is supported by SQLite but not the other three db
• TEMPORARY is supported by PostgreSQL and SQLite but not the other two db
• RECURSIVE is supported only by PostgreSQL
• WITH [ CASCADED | LOCAL ]...

And, the list goes on. I think it's better to document these db specific features later in this PR. Or, even, dump some of the feature that supported by only one db.

References:

• https://dev.mysql.com/doc/refman/8.0/en/create-view.html
• https://mariadb.com/kb/en/create-view/
• https://www.postgresql.org/docs/current/sql-createview.html
• https://www.sqlite.org/lang_createview.html

I understood this. My question was: #293 (comment)

[tyt2y3]

I think ViewCreateStatement should impl QueryStatementBuilder.
May be we can forget ViewStatement for now, if we do keep it then all methods should return (String, Values)

[ian-p-cooke]

status?

[ikrivosheev]

status?

@ian-p-cooke hello! I am working on support Postgres array in SeaQuery. After I will return back to this PR.

[ikrivosheev]

Well, It's time to continue working on this PR.

[LucaRickler]

Any news on this?