feat: implement BIT support in MSSQL

sqlx-core/src/mssql/protocol/type_info.rs

@@ -491,6 +491,7 @@ impl TypeInfo {
             DataType::BigInt => s.push_str("bigint"),
             DataType::Real => s.push_str("real"),
             DataType::Float => s.push_str("float"),
+            DataType::Bit => s.push_str("bit"),
 
             DataType::IntN => s.push_str(match self.size {
                 1 => "tinyint",
@@ -536,6 +537,10 @@ impl TypeInfo {
                 }
             }
 
+            DataType::BitN => {
+                s.push_str("bit");
+            }
+
             _ => unimplemented!("fmt: unsupported data type {:?}", self.ty),
         }
     }

sqlx-core/src/mssql/types/bool.rs

@@ -0,0 +1,30 @@
+use crate::decode::Decode;
+use crate::encode::{Encode, IsNull};
+use crate::error::BoxDynError;
+use crate::mssql::protocol::type_info::{DataType, TypeInfo};
+use crate::mssql::{Mssql, MssqlTypeInfo, MssqlValueRef};
+use crate::types::Type;
+
+impl Type<Mssql> for bool {
+    fn type_info() -> MssqlTypeInfo {
+        MssqlTypeInfo(TypeInfo::new(DataType::BitN, 1))
+    }
+}
+
+impl Encode<'_, Mssql> for bool {
+    fn encode_by_ref(&self, buf: &mut Vec<u8>) -> IsNull {
+        buf.push(if *self { 1 } else { 0 });
+
+        IsNull::No
+    }
+}
+
+impl Decode<'_, Mssql> for bool {
+    fn accepts(ty: &MssqlTypeInfo) -> bool {
+        matches!(ty.0.ty, DataType::Bit | DataType::BitN)
+    }
+
+    fn decode(value: MssqlValueRef<'_>) -> Result<Self, BoxDynError> {
+        Ok(value.as_bytes()?[0] == 1)
+    }
+}

sqlx-core/src/mssql/types/mod.rs

@@ -2,6 +2,7 @@ use crate::encode::{Encode, IsNull};
 use crate::mssql::protocol::type_info::{DataType, TypeInfo};
 use crate::mssql::{Mssql, MssqlTypeInfo};
 
+mod bool;
 mod float;
 mod int;
 mod str;

tests/mssql/types.rs

@@ -35,3 +35,9 @@ test_type!(str<String>(Mssql,
     "'this is foo'" == "this is foo",
     "''" == "",
 ));
+
+test_type!(bool(
+    Mssql,
+    "CAST(1 as BIT)" == true,
+    "CAST(0 as BIT)" == false
+));