# ClickHouse + URLEng

# Serverless ClickHouse URL Engine

### 👇 Ready? Get your own table in zero minutes ⏱️

You're about to create your very own serverless, storage persistent URL Engine table - fast, free and always accessible from anywhere. Since there are no logins or signups, all data is hidden in public. The only protection is your own **secret URL path**.

### Choose a unique URL path

We will use the ClickHouse **URL Engine** to query data _to/from_ our service.

- Open your **ClickHouse** client
- Choose your unique **URL path** 

> Replace `mY5uPeRs3Cre7tok3N` with your Token!

To avoid typing this every time, we'll store our URL as a _variable_

```
:) SET param_url = 'https://urleng.com/mY5uPeRs3Cre7tok3N'
```

### INSERT data
It's time to insert some data. 

The serverless table will automatically adapt to the schema inserts.
```
:) INSERT INTO FUNCTION url({url:String}, JSONEachRow, 'key String, value UInt64') VALUES ('hello', 1)
```

### SELECT data
Let's read our data back and apply some logic for fun. 

Note due to how ClickHouse works, the full table gets read each time.
```
:) SELECT * FROM url({url:String}, JSONEachRow)
```

### CREATE URL Table
If you plan on using the data frequently, you can create a persistent URL Engine table. 

Choose any schema, too.
```
:) CREATE TABLE default.url_engine_distributed
 (
 `key` String,
 `value` UInt64,
 )
 ENGINE = URL('https://urleng.com/mY5uPeRs3Cre7tok3N', 'JSONEachRow')

:) INSERT INTO url_engine_distributed VALUES ('hello', 1), ('world', 2)
:) SELECT * FROM url_engine_distributed

┌─key──┬─value┐
│ hello │ 1 │
│ world │ 2 │
└─────┴─────┘

2 rows in set. Elapsed: 0.185 sec.
```

### EXPIRE/TTL Data
You can expire data by using or adding an __expires key/column with a future unix timestamp.
```
:) INSERT INTO FUNCTION url({url:String}, JSONEachRow, 'key String, value UInt64, __expires UInt64')
   VALUES ('hello', 1, toUnixTimestamp(now()+300))
```

### CLICKHOUSE Local
No server? Get your table data in/out of your table using `clickhouse-local`
```
clickhouse-local -q "select count() from url('https://urleng.com/mY5uPeRs3Cre7tok3N', JSONEachRow)"
```

### CURL
Last but not least, data can be inserted and accessed through curl or any other HTTP GET/POST capable client.
#### POST ndjson
```
curl -s -XPOST https://urleng.com/mY5uPeRs3Cre7tok3N-H 'Content-Type:application/x-ndjson' --data-binary @ndjson.txt
```
#### POST json
```
curl -X POST https://url-engine.metrico.in/mY5uPeRs3Cre7tok3N-H 'Content-Type: application/json' -d '[{"key":"curl","value":1}]'
``` 

#### GET json
```
curl -X GET https://urleng.com/mY5uPeRs3Cre7tok3N
```

<br>

## That's it

Enjoy your free, bottomless URL table! Use it to share small datasets, states, k/vs and anything you can think of between your nodes as if they were a distributed cluster.

💬 Found a problem? Got some feedback or ideas? Please open an Issue or start a Discussion in our community

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