add test cases of test_show in http_test (infiniflow#1659)

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

### Type of change


- [x] Test cases

python/test_http_api/test_show.py

@@ -78,3 +78,59 @@ def test_http_show_columns(self):
 
         self.drop_table(db_name, table_name)
         return
+
+    def test_http_show_table_after_insert(self):
+        db_name = "default_db"
+        table_name = "test_http_show_table_fater_insert"
+
+        self.drop_table(db_name, table_name)
+
+        self.create_table(
+            db_name, table_name, [
+                {
+                    "name": "num",
+                    "type": "integer",
+                },
+                {
+                    "name": "body",
+                    "type": "varchar",
+                },
+                {
+                    "name": "vec",
+                    "type": "vector",
+                    "dimension": 5,
+                    "element_type": "float",
+                }
+            ]
+        )
+
+        self.insert_data(
+            db_name, table_name, [
+                {"num": 1, "body": "test", "vec": [0.1, 0.2, 0.3, 0.4, 0.5]},
+                {"num": 2, "body": "sample", "vec": [0.2, 0.3, 0.4, 0.5, 0.6]}
+            ]
+        )
+
+        self.show_table(db_name, table_name, {
+            "error_code": 0,
+            "database_name": db_name,
+            "table_name": table_name,
+            "column_count": 3,
+            "row_count": 2
+        })
+
+        self.drop_table(db_name, table_name)
+        return
+
+    def test_http_show_nonexistent_table(self):
+        db_name = "default_db"
+        table_name = "nonexistent_table"
+
+        self.show_table(db_name, table_name, {
+            "status_code": 404,
+            "error_code": 1004,
+            "message": f"Table {table_name} do not exist in database {db_name}."
+        })
+        return
+
+