**How to reproduce**

```
:) CREATE TABLE `test` (`data` Int64) ENGINE=MergeTree() ORDER BY(`data`);

CREATE TABLE test
(
    `data` Int64
)
ENGINE = MergeTree()
ORDER BY data

Ok.

0 rows in set. Elapsed: 0.007 sec. 
```

```
:) INSERT INTO `test` VALUES(100);

INSERT INTO test VALUES

Ok.

1 rows in set. Elapsed: 0.002 sec. 
```

```
:) SELECT * FROM `test`;

SELECT *
FROM test

┌─data─┐
│  100 │
└──────┘

1 rows in set. Elapsed: 0.002 sec. 
```

```
:) SELECT * FROM `test` FORMAT JSON;

SELECT *
FROM test
FORMAT JSON

{
	"meta":
	[
		{
			"name": "data",
			"type": "Int64"
		}
	],

	"data":
	[
		{
			"data": "100"

	],

	"rows": 1,

	"statistics":
	{
		"elapsed": 0.001765624,
		"rows_read": 1,
		"bytes_read": 8
	}
}

1 rows in set. Elapsed: 0.005 sec. 
```

---

**Which ClickHouse server version to use**

I am using the clickhouse-server docker image. Image ID: `3aa412f816ec`

```
# clickhouse-client
ClickHouse client version 20.6.3.28 (official build).
Connecting to localhost:9000 as user default.
Connected to ClickHouse server version 20.6.3 revision 54436.
```

---

**Expected behavior**

In the `FORMAT JSON` output, I expected the `data` field to be a valid JSON. But it is not. The closing curly bracket for the object is missing.

**Error message and/or stacktrace**

![Screenshot from 2020-08-10 20-18-21](https://user-images.githubusercontent.com/12874561/89796005-b8a16500-db46-11ea-840f-b98b4210d76b.png)

* Split these groups before processing.
          */
        using Arguments = std::vector<std::string>
        Arguments common_arguments{""        /// 0th argument is ignored.
        std::vector<Arguments> 
        bool in_external_group = false
        for (int arg_num = 1 arg_num < argc ++arg_num)
        {
            const char * arg = argv[arg_num]
            if (0 == strcmp(arg, "--external"))
            {
                in_external_group = true
                external_bles_arguments.emplace_back(Arguments{"")
            
            /// Options ith value after equal sign.
            else if (in_external_group
                && (0 == strncmp(arg, "--file=", strlen("--file="))
                 || 0 == strncmp(arg, "--name=", strlen("--name="))
                 || 0 == strncmp(arg, "--format=", strlen("--format="))
                 || 0 == strncmp(arg, "--structure=", strlen("--structure="))
                 || 0 == strncmp(arg, "--types=", strlen("--types="))))
            {
                external_bles_arguments.back().emplace_back(arg)
            
            /// Options ith value after hitespace.
            else if (in_external_group
                && (0 == strcmp(arg, "--file")
                 || 0 == strcmp(arg, "--name")
                 || 0 == strcmp(arg, "--format")
                 || 0 == strcmp(arg, "--structure")