{"id":2887,"date":"2021-05-04T10:46:00","date_gmt":"2021-05-03T22:46:00","guid":{"rendered":"https:\/\/www.talkcrypto.org\/blog\/?p=2887"},"modified":"2023-11-28T01:08:20","modified_gmt":"2023-11-27T12:08:20","slug":"part-1-subql-hello-world-in-less-than-5-mins","status":"publish","type":"post","link":"https:\/\/www.talkcrypto.org\/blog\/2021\/05\/04\/part-1-subql-hello-world-in-less-than-5-mins\/","title":{"rendered":"Part 1: SubQuery (aka Subql) Hello World in less than 5 mins"},"content":{"rendered":"\n
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Introduction<\/h2>\n\n\n\n
They say that cooking is quick and easy, it’s the preparation that takes all the time. In coding, it is no different. Getting a Hello World example up and running is quick, but the preparation takes a bit of time. Here we’ll spin up a Hello World sample in less than 5 mins but only if you have the right ingredients. This example will spin up a Subql node, a Graphql engine and a Postgres database. It will then synchronise with the live Polkadot mainnet blockchain, and then allow you to query for the block height. <\/p>\n\n\n\n
First, let’s do a quick pre-requisite check.<\/p>\n\n\n\n
You should get something like: <\/p>\n\n\n\n<\/figure>\n\n\n\n
The block count in the playground should match the block count (technically the block height) in the terminal.<\/p>\n\n\n\n<\/figure>\n\n\n\n
<\/p>\n\n\n\n
You may also notice that the output gives an indication of how long it will take to fully synch with Polkadot mainnet. At the time of writing, this would take me about one and a half days!<\/p>\n\n\n\n<\/figure>\n\n\n\n
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Summary<\/h2>\n\n\n\n
There you have it. A Subql Hello World example up in less than 5 minutes. Assuming you had all the ingredients of course :). What did we do? We initialised a starter project template that was pre-populated with a simple query, ie code was provided for us already, the code also spun up a node, synchronise it, and then we queired the live Polkadot mainnet for the block height. <\/p>\n\n\n\n
Where to from here? Let’s take a deeper dive at what is happening under the covers.<\/p>\n\n\n\n
<\/p>\n\n\n\n
Bloopers<\/h2>\n\n\n\n
Using spaces?<\/h3>\n\n\n\n
If you use spaces in your project name you will get the following error. No spaces please!<\/p>\n\n\n\n
seandotau$ subql init --starter subql hello world\n \u203a Error: Unexpected arguments: hello, world\n \u203a See more help with --help<\/code><\/pre>\n\n\n\n
Not a Number?<\/h3>\n\n\n\n
NaN bps, target: #5379522, current: #690, estimate time: NaN days NaN hours NaN mins <\/code><\/pre>\n\n\n\n
NaN? This tends to indicate a connectivity error. Try to restart the docker container. ie stop docker with ctrl+c and then run <\/p>\n\n\n\n
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