fisrt

public/vendor/js/setStock.js

@@ -0,0 +1,21 @@
+$('.join_identity_id').change(function (e) {
+    const val = $(this).val();
+    var commonThis = $(this);
+    if (val !== null) {
+        $.ajax({
+            type: "get",
+            data: {
+                'q': val,
+            },
+            url: "/admin/platform/identity_stock",
+            async: true,
+            success: (result => {
+                if (result.status_code == 200) {
+                    $('.stock').val(result.value);
+                } else {
+                    alert('获取库存失败');
+                }
+            })
+        });
+    }
+});