support bigger blob

[hunjixin]

PR Info

support medium blob longblob type

Adds

Breaking Changes

Changes

this implement is a little track , but in the current implementation there is specific blob type

[tyt2y3]

This does not seem right. We should instead add more variants to ColumnType

[billy1624]

This does not seem right. We should instead add more variants to ColumnType

But then all these new types, mediumblob and longblob, are not supported in other db backend. Hence, it will be maps to blob datatype in other db. Hope it won't confuse the users.

[hunjixin]

This does not seem right. We should instead add more variants to ColumnType

But then all these new types, mediumblob and longblob, are not supported in other db backend. Hence, it will be maps to blob datatype in other db. Hope it won't confuse the users.

best way to support blob is add new column type.
It may not be practical to use a set of type system to completely unify the types of several databases.
consider anyway to enable the database to support unique types

[billy1624]

consider anyway to enable the database to support unique types

Are you suggesting ColumnType that are feature guarded by db backend? I don't think this is a good idea. We try to avoid relying on feature guard by db backend.

But then all these new types, mediumblob and longblob, are not supported in other db backend. Hence, it will be maps to blob datatype in other db.

This will be a good middle ground for me though we have to be explicit these new column types are primarily added for MySQL.

[tyt2y3]

I think a blob type with a enum BlobSize param makes the most sense

[billy1624]

I think a blob type with a enum BlobSize param makes the most sense

You mean blob type with an Option<BlobSize> param?

[tyt2y3]

Okay this might not actually be relevant.

My rule of thumb is "anything that exists conceptually deserves to be named accordingly".

[tyt2y3]

It could be

enum BlobSize {
Default,
Medium,
Long,
}

so we don't need an Option

[billy1624]

Hey @hunjixin, got any updates? :)

[hunjixin]

Hey @hunjixin, got any updates? :)

add new columntype "BLOB" to support this feature? if all think it okay, i'd like to implement one, but i am not sure whether affect other db types, maybe need help.

[billy1624]

My plans are...

1. Add BlobSize to Binary variant in ColumnType enum

   Binary(BlobSize)

   With BlobSize defined as

   enum BlobSize {
       Default(Option<u32>), // Backward compatibility: MySQL & SQLite support `binary(length)` column type
       Medium,
       Long,
   }

2. Add helper methods to ColumnDef, namely binary_medium and binary_long
3. Update SQL builder in all three backends, if binary_medium and binary_long are not support in a particular backend then both of them will be mapped to binary

CC @tyt2y3 @hunjixin

[hunjixin]

My plans are...

1. Add BlobSize to Binary variant in ColumnType enum

   Binary(BlobSize)

   With BlobSize defined as

   enum BlobSize {
       Default(Option<u32>), // Backward compatibility: MySQL & SQLite support `binary(length)` column type
       Medium,
       Long,
   }

2. Add helper methods to ColumnDef, namely binary_medium and binary_long

3. Update SQL builder in all three backends, if binary_medium and binary_long are not support in a particular backend then both of them will be mapped to binary

CC @tyt2y3 @hunjixin

see your idea, but have two suggestions

1. its better to include blob/tinyblob include blobsize?

#[derive(Debug, Clone)]
enum BlobSize {
    Default(Option<u32>), // Backward compatibility: MySQL & SQLite support `binary(length)` column type
    Tiny,
    Blob,  //default blob, need a better name?
    Medium,
    Long,
}

2. maybe more appropriate to add the blob method, so as not to be confused with binary

    /// Set column type as blob
    pub fn blob(&mut self, size: BlobSize) -> &mut Self {
        //todo need to check set default size or convert to correct blob type?
        self.types = Some(ColumnType::Binary(size));
        self
    }

[hunjixin]

@billy1624 updated pr

[billy1624]

LGTM! Thanks! @hunjixin

[billy1624]

I will updates the downstream accordingly

• MySQL blob datatype maps to SeaQuery corresponding blob column type sea-schema#61
• CLI & Codegen: Treat MySQL blob column as Vec<u8> in Rust sea-orm#685

[tyt2y3]

Thank you for the patience @hunjixin