SeaQL/sea-orm · critical

Failed to get json

Error message

Failed to get json

What it means

This panic occurs when sea-orm's Postgres driver cannot decode a JSON/JSONB column into Option<serde_json::Value> (requires `with-json`). try_get fails when the cell is not actually json/jsonb on the wire (e.g. it is text), or the sqlx build lacks json support so the decode is rejected. Because the code uses `.expect`, the failure is a panic instead of a returned error.

Source

Thrown at sea-orm-sync/src/driver/sqlx_postgres.rs:643

                        }
                        #[cfg(feature = "postgres-array")]
                        "OID[]" => Value::Array(
                            sea_query::ArrayType::BigInt,
                            row.try_get::<Option<Vec<i64>>, _>(c.ordinal())
                                .expect("Failed to get oid array")
                                .map(|vals| {
                                    Box::new(
                                        vals.into_iter()
                                            .map(|val| Value::BigInt(Some(val)))
                                            .collect(),
                                    )
                                }),
                        ),

                        #[cfg(feature = "with-json")]
                        "JSON" | "JSONB" => Value::Json(
                            row.try_get::<Option<serde_json::Value>, _>(c.ordinal())
                                .expect("Failed to get json")
                                .map(Box::new),
                        ),
                        #[cfg(all(
                            feature = "with-json",
                            any(feature = "json-array", feature = "postgres-array")
                        ))]
                        "JSON[]" | "JSONB[]" => Value::Array(
                            sea_query::ArrayType::Json,
                            row.try_get::<Option<Vec<serde_json::Value>>, _>(c.ordinal())
                                .expect("Failed to get json array")
                                .map(|vals| {
                                    Box::new(
                                        vals.into_iter()
                                            .map(|val| Value::Json(Some(Box::new(val))))
                                            .collect(),
                                    )
                                }),
                        ),

View on GitHub (pinned to e29bcd1b41)

Solutions

1. Ensure the `with-json` feature is enabled consistently on sea-orm and that the sqlx version it pulls supports json decoding.
2. Verify the column type with `SELECT pg_typeof(col)`; cast explicitly if a query returns text: `col::jsonb`.
3. Avoid UNION/CASE mixes that downgrade jsonb to text; cast each branch to jsonb.
4. Run `cargo tree -i sqlx` to confirm a single sqlx version with the json feature is linked.

Example fix

// before
SELECT CASE WHEN ok THEN data ELSE 'null' END AS data FROM t;

// after
SELECT CASE WHEN ok THEN data ELSE 'null'::jsonb END::jsonb AS data FROM t;

// Check that the JSON feature set is coherent and the column is really json/jsonb:
let t = db.query_one(Statement::from_string(
    DatabaseBackend::Postgres,
    "SELECT pg_typeof(data)::text FROM t LIMIT 1",
)).await?;
// expect "json" or "jsonb"

// Since this is a panic, avoid it by decoding nullable-json via raw SQL with an explicit cast:
let rows = db.query_all(Statement::from_string(
    DatabaseBackend::Postgres,
    "SELECT data::jsonb FROM t",
)).await?;
// then try_get::<Option<serde_json::Value>, _>(0)? returns a Result you can handle.

When it happens

Trigger: Selecting a JSON/JSONB column via raw SQL where the driver returns the type under a different name (e.g. from a view or a `to_jsonb(...)` in a context that yields text), or with the `with-json` feature disabled in the sqlx dependency while sea-orm compiled the JSON branch, or deserializing from a connection built with mismatched feature sets.

Common situations: Feature-flag drift between sea-orm and sqlx in the workspace (one crate enables with-json, another doesn't); reading JSON columns through UNION/CASE expressions where Postgres infers text; older sqlx versions with jsonb decoding bugs.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Failed to get json array
• Failed to get numeric array
• Failed to get oid
• Failed to get oid array
• Failed to get ip address

AI-assisted analysis of SeaQL/sea-orm@e29bcd1b41 (2026-09-10). Data as JSON: /api/errors/61312b9c0bc52b72. Report an issue: GitHub.