fix(macros): reintroduce and fix macro tests for MySQL

sqlx-core/src/mysql/connection/executor.rs

@@ -275,9 +275,10 @@ impl<'c> Executor<'c> for &'c mut MySqlConnection {
                 for _ in 0..(ok.columns as usize) {
                     let def: ColumnDefinition = self.stream.recv().await?;
                     let ty = MySqlTypeInfo::from_column(&def);
+                    let name = def.name()?;
 
                     columns.push(Column {
-                        name: def.name()?.to_owned(),
+                        name: if name.is_empty() { def.alias()? } else { name }.to_owned(),
                         type_info: ty,
                         not_null: Some(def.flags.contains(ColumnFlags::NOT_NULL)),
                     })

sqlx-core/src/mysql/type_info.rs

@@ -78,6 +78,18 @@ impl PartialEq<MySqlTypeInfo> for MySqlTypeInfo {
                     == other.flags.contains(ColumnFlags::UNSIGNED);
             }
 
+            // for string types, check that our charset matches
+            ColumnType::VarChar
+            | ColumnType::Blob
+            | ColumnType::TinyBlob
+            | ColumnType::MediumBlob
+            | ColumnType::LongBlob
+            | ColumnType::String
+            | ColumnType::VarString
+            | ColumnType::Enum => {
+                return self.char_set == other.char_set;
+            }
+
             _ => {}
         }
 

sqlx-core/src/mysql/types/str.rs

@@ -36,7 +36,7 @@ impl<'r> Decode<'r, MySql> for &'r str {
                 | ColumnType::String
                 | ColumnType::VarString
                 | ColumnType::Enum
-        )
+        ) && ty.char_set == 224
     }
 
     fn decode(value: MySqlValueRef<'r>) -> Result<Self, BoxDynError> {