Add some type support.

I think ideally we'd be able to get the name from the driver rather than
defaulting to the c-api's name, but I'm not sure how possible that is at
this time.

This seems like a fine intermediary for now.

Closes #3

Co-authored-by:  Roman TSovanyan <[email protected]>

mysql_test.go

@@ -108,7 +108,8 @@ func TestMYSQLScanType(t *testing.T) {
 
 	for _, colType := range cTypes {
 		typ := *colType
-		assert.Equal(t, reflect.TypeOf(int64(0)), typ.ScanType())
+		assert.Equal(t, reflect.TypeOf(int32(0)), typ.ScanType())
+		assert.Equal(t, "SQL_C_LONG", typ.DatabaseTypeName())
 	}
 	rows.Close()
 

rows.go

@@ -77,3 +77,54 @@ func (r *Rows) ColumnTypeScanType(index int) reflect.Type {
 func (r *Rows) ColumnTypeNullable(index int) (nullable, ok bool) {
 	return r.s.cols[index].Nullable()
 }
+
+// ColumnTypeDatabaseTypeName return the database system type name.
+func (r *Rows) ColumnTypeDatabaseTypeName(index int) string {
+	switch x := r.s.cols[index].(type) {
+	case *BindableColumn:
+		return cTypeString(x.CType)
+	case *NonBindableColumn:
+		return cTypeString(x.CType)
+	}
+	return ""
+}
+
+func cTypeString(ct api.SQLSMALLINT) string {
+	switch ct {
+	case api.SQL_C_CHAR:
+		return "SQL_C_CHAR"
+	case api.SQL_C_LONG:
+		return "SQL_C_LONG"
+	case api.SQL_C_SHORT:
+		return "SQL_C_SHORT"
+	case api.SQL_C_FLOAT:
+		return "SQL_C_FLOAT"
+	case api.SQL_C_DOUBLE:
+		return "SQL_C_DOUBLE"
+	case api.SQL_C_NUMERIC:
+		return "SQL_C_NUMERIC"
+	case api.SQL_C_DATE:
+		return "SQL_C_DATE"
+	case api.SQL_C_TIME:
+		return "SQL_C_TIME"
+	case api.SQL_C_TYPE_TIMESTAMP:
+		return "SQL_C_TYPE_TIMESTAMP"
+	case api.SQL_C_TIMESTAMP:
+		return "SQL_C_TIMESTAMP"
+	case api.SQL_C_BINARY:
+		return "SQL_C_BINARY"
+	case api.SQL_C_BIT:
+		return "SQL_C_BIT"
+	case api.SQL_C_WCHAR:
+		return "SQL_C_WCHAR"
+	case api.SQL_C_DEFAULT:
+		return "SQL_C_DEFAULT"
+	case api.SQL_C_SBIGINT:
+		return "SQL_C_SBIGINT"
+	case api.SQL_C_UBIGINT:
+		return "SQL_C_UBIGINT"
+	case api.SQL_C_GUID:
+		return "SQL_C_GUID"
+	}
+	return ""
+}