fix: Use rfc3339 to decode date from text

sqlx-postgres/src/types/chrono/datetime.rs

@@ -86,25 +86,71 @@ impl<Tz: TimeZone> Encode<'_, Postgres> for DateTime<Tz> {
 
 impl<'r> Decode<'r, Postgres> for DateTime<Local> {
     fn decode(value: PgValueRef<'r>) -> Result<Self, BoxDynError> {
-        let naive = <NaiveDateTime as Decode<Postgres>>::decode(value)?;
-        Ok(Local.from_utc_datetime(&naive))
+        let fixed = <DateTime<FixedOffset> as Decode<Postgres>>::decode(value)?;
+        Ok(Local.from_utc_datetime(&fixed.naive_utc()))
     }
 }
 
 impl<'r> Decode<'r, Postgres> for DateTime<Utc> {
     fn decode(value: PgValueRef<'r>) -> Result<Self, BoxDynError> {
-        let naive = <NaiveDateTime as Decode<Postgres>>::decode(value)?;
-        Ok(Utc.from_utc_datetime(&naive))
+        let fixed = <DateTime<FixedOffset> as Decode<Postgres>>::decode(value)?;
+        Ok(Utc.from_utc_datetime(&fixed.naive_utc()))
     }
 }
 
 impl<'r> Decode<'r, Postgres> for DateTime<FixedOffset> {
     fn decode(value: PgValueRef<'r>) -> Result<Self, BoxDynError> {
-        let naive = <NaiveDateTime as Decode<Postgres>>::decode(value)?;
-        Ok(Utc.fix().from_utc_datetime(&naive))
+        Ok(match value.format() {
+            PgValueFormat::Binary => {
+                let naive = <NaiveDateTime as Decode<Postgres>>::decode(value)?;
+                Utc.fix().from_utc_datetime(&naive)
+            }
+
+            PgValueFormat::Text => {
+                let s = value.as_str()?;
+                decode_datetime_from_text(s)
+            }
+        })
     }
 }
 
+fn decode_datetime_from_text(value: &str) -> DateTime<FixedOffset> {
+    if let Ok(dt) = DateTime::parse_from_rfc3339(value) {
+        return dt;
+    }
+
+    // Loop over common date time patterns, inspired by Diesel
+    // https://github.com/diesel-rs/diesel/blob/93ab183bcb06c69c0aee4a7557b6798fd52dd0d8/diesel/src/sqlite/types/date_and_time/chrono.rs#L56-L97
+    let sqlite_datetime_formats = &[
+        // Most likely format
+        "%F %T%.f",
+        // Other formats in order of appearance in docs
+        "%F %R",
+        "%F %RZ",
+        "%F %R%:z",
+        "%F %T%.fZ",
+        "%F %T%.f%:z",
+        "%FT%R",
+        "%FT%RZ",
+        "%FT%R%:z",
+        "%FT%T%.f",
+        "%FT%T%.fZ",
+        "%FT%T%.f%:z",
+    ];
+
+    for format in sqlite_datetime_formats {
+        if let Ok(dt) = DateTime::parse_from_str(value, format) {
+            return dt;
+        }
+
+        if let Ok(dt) = NaiveDateTime::parse_from_str(value, format) {
+            return Utc.fix().from_utc_datetime(&dt);
+        }
+    }
+
+    panic!("BUG: failed to parse {value:?} as a DateTime")
+}
+
 #[inline]
 fn postgres_epoch_datetime() -> NaiveDateTime {
     NaiveDate::from_ymd_opt(2000, 1, 1)