Add support for extra non-standard "DATETIME UTC" type for sqlite

This allows us to explicitly opt into using `DateTime<Utc>` instead of `NaiveDateTime` without doing conversions at query time (either via `col as "col: DateTime<Utc>" or mapping the results manually).

Ref: launchbadge#598 (comment)

Author: tgecho

sqlx-sqlite/src/type_info.rs

@@ -27,6 +27,7 @@ pub(crate) enum DataType {
     Date,
     Time,
     Datetime,
+    DatetimeUtc,
 }
 
 /// Type information for a SQLite type.
@@ -59,6 +60,7 @@ impl TypeInfo for SqliteTypeInfo {
             DataType::Date => "DATE",
             DataType::Time => "TIME",
             DataType::Datetime => "DATETIME",
+            DataType::DatetimeUtc => "DATETIME UTC",
         }
     }
 }
@@ -94,6 +96,7 @@ impl FromStr for DataType {
             "date" => DataType::Date,
             "time" => DataType::Time,
             "datetime" | "timestamp" => DataType::Datetime,
+            "datetime utc" | "timestamp utc" => DataType::DatetimeUtc,
 
             _ if s.contains("int") => DataType::Int64,
 
@@ -149,5 +152,7 @@ fn test_data_type_from_str() -> Result<(), BoxDynError> {
     assert_eq!(DataType::Time, "TIME".parse()?);
     assert_eq!(DataType::Date, "DATE".parse()?);
 
+    assert_eq!(DataType::DatetimeUtc, "DATETIME UTC".parse()?);
+
     Ok(())
 }

sqlx-sqlite/src/types/chrono.rs

@@ -15,11 +15,11 @@ use chrono::{
 
 impl<Tz: TimeZone> Type<Sqlite> for DateTime<Tz> {
     fn type_info() -> SqliteTypeInfo {
-        SqliteTypeInfo(DataType::Datetime)
+        SqliteTypeInfo(DataType::DatetimeUtc)
     }
 
     fn compatible(ty: &SqliteTypeInfo) -> bool {
-        <NaiveDateTime as Type<Sqlite>>::compatible(ty)
+        matches!(ty.0, DataType::DatetimeUtc) || <NaiveDateTime as Type<Sqlite>>::compatible(ty)
     }
 }