unsupported jsonb number 123

[rrichardson]

Setup

osx brew install postgres

$ otool -L target/debug/fries
target/debug/fries:
/usr/local/opt/postgresql/lib/libpq.5.dylib (compatibility version 5.0.0, current version 5.10.0)

[dependencies]
diesel = { version = "1.0.0", features = ["postgres", "serde_json"] }

Versions

• Rust: .rustc 1.27.1 (5f2b325f6 2018-07-07)
• Diesel: 1.0.0
• Database: . Postgresql 9.6 or 10, libpq 5.10
• Operating System . OSX High Sierra

Feature Flags

• diesel: . postgres . serde_json

Problem Description

When running my importer app, it fails to insert into a Jsonb field and errors with:

DatabaseError(__Unknown, "unsupported jsonb version number 123")

I reckon it is related to lib/pq#528
This makes me think that maybe serializing the json into a byte array is the wrong thing.. but I'm not sure what the correct approach is.. (see fn to_sql below)

What are you trying to accomplish?

Insert my custom serde_json type into a jsonb column

What is the expected output?

Success

What is the actual output?

DatabaseError(__Unknown, "unsupported jsonb version number 123")

Are you seeing any additional errors?

None that I can find

Steps to reproduce

#[serde(rename_all = "kebab-case")]
#[derive(Serialize, Deserialize, Debug, PartialEq, FromSqlRow, AsExpression)]
#[sql_type="Jsonb"]
pub struct Pos {
    object_type: String,
    reference: String,
    offset: i32,
    is_closed: Option<bool>,
}

impl ToSql<Jsonb, Pg> for Pos {
    fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> serialize::Result {
        let j = serde_json::to_string(self)?;
        out.write_all(j.as_bytes())?;
        Ok(IsNull::No)
    }
}

impl FromSql<Jsonb, Pg> for Pos {
    fn from_sql(bytes: Option<&[u8]>) -> deserialize::Result<Self> {
        let p : Pos = serde_json::from_slice(not_none!(bytes))?;
        Ok(p)
    }
}

#[serde(rename_all = "kebab-case")]
#[derive(Insertable, Queryable, Deserialize)]
#[table_name="sentences"]
pub struct Sentence {
  start_pos: Pos,
  end_pos: Pos,
}

table! {
    sentences (id) {
        start_pos -> Nullable<Jsonb>,
        end_pos -> Nullable<Jsonb>,
    }
}

Checklist

• [x ] I have already looked over the issue tracker for similar issues.
• [x ] This issue can be reproduced on Rust's stable channel. (Your issue will be
  closed if this is not the case)

[rrichardson]

Found the problem. Since I'm providing the binary format, I need to prefix the value with 1 as is done in the ToSql impl for serde_json::Value.

[sgrif]

You should avoid relying on the concrete representation of PG's json types or Diesel specific implementations. Instead you should work in terms of serde_json::Value types, which are already supported, and then call that types ToSql/FromSql implementations.