query test progress

src/database/relation.rs

@@ -0,0 +1,12 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+#[serde(default)]
+pub struct Relation {
+  pub constraint: String,
+  pub source_type: String,
+  pub source_columns: Vec<String>,
+  pub destination_type: String,
+  pub destination_columns: Vec<String>,
+  pub prefix: Option<String>,
+}