diff --git a/jq.md b/jq.md
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--- a/jq.md
+++ b/jq.md
@@ -1 +1,30 @@
-example
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+## null
+
+`id:3`の`name:null`を除外して表示
+
+```json
+[
+  {
+    "id": 1,
+    "name": "aios",
+    "display": "ai os"
+  },
+  {
+    "id": 2,
+    "name": "archlinux",
+    "display": "Arch Linux"
+  },
+  {
+    "id": 3,
+    "display": "Linux Kernel"
+  }
+]
+```
+
+```sh
+$ echo $json|jq -r ".[]|{name, display}|select(.name | length > 0)|.name,.display"
+aios
+ai os
+archlinux
+Arch Linux
+```
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