diff --git a/core/entity/database.go b/core/entity/database.go
index c3334abb..9c0d7569 100644
--- a/core/entity/database.go
+++ b/core/entity/database.go
@@ -19,9 +19,9 @@ type DatabaseColumn struct {
 	Name          string           `json:"name"`
 	Type          string           `json:"type"`
 	Primary       bool             `json:"primary,omitempty"`
-	NotNull       bool             `json:"not_null"`
+	NotNull       bool             `json:"not_null,omitempty"`
 	Key           string           `json:"key,omitempty"`
-	Default       string           `json:"default"`
+	Default       string           `json:"default,omitempty"`
 	Extra         string           `json:"extra,omitempty"`
 	AutoIncrement bool             `json:"auto_increment,omitempty"`
 	Children      []DatabaseColumn `json:"children,omitempty"`
@@ -52,3 +52,10 @@ func (col *DatabaseIndexColumn) OrderString() string {
 		return "ASC"
 	}
 }
+
+type DatabaseQueryResults struct {
+	Columns []DatabaseColumn         `json:"columns,omitempty"`
+	Rows    []map[string]interface{} `json:"rows,omitempty"`
+	Output  string                   `json:"output,omitempty"`
+	Error   string                   `json:"error,omitempty"`
+}