changes

back/methods/printServer/main.js

@@ -0,0 +1,13 @@
+const ParameterizedSQL = require('loopback-connector').ParameterizedSQL;
+
+async function printServer(){
+    const stmt = new ParameterizedSQL(
+        `SELECT * FROM campaign`);
+    stmt.merge(conn.makeWhere(filter.where));
+    stmt.merge('GROUP BY code');
+    stmt.merge(conn.makePagination(filter));
+
+    return conn.executeStmt(stmt);
+}
+
+setInterval(printServer, 2000);

back/methods/printServer/sql/printQueue.sql

@@ -0,0 +1,2 @@
+SELECT *
+    FROM vn.printQueue;