How to get current timestamp with CQL while using Command Line

cassandracqldatastax-java-drivertimestamp

I am trying to insert into my CQL table from the command line. I am able to insert everything. But I am wondering if I have a timestamp column, then how can I insert into timestamp column from the command line? Basically, I want to insert current timestamp whenever I am inserting into my CQL table –

Currently, I am hardcoding the timestamp whenever I am inserting into my below CQL table –

CREATE TABLE TEST (ID TEXT, NAME TEXT, VALUE TEXT, LAST_MODIFIED_DATE TIMESTAMP, PRIMARY KEY (ID));

INSERT INTO TEST (ID, NAME, VALUE, LAST_MODIFIED_DATE) VALUES ('1', 'elephant',  'SOME_VALUE', 1382655211694);

Is there any way to get the current timestamp using some predefined functions in CQL so that while inserting into above table, I can use that method to get the current timestamp and then insert into above table?

Best Answer

You can use the timeuuid functions now() and dateof() (or in later versions of Cassandra, toTimestamp()), e.g.,

INSERT INTO TEST (ID, NAME, VALUE, LAST_MODIFIED_DATE)
                  VALUES ('2', 'elephant',  'SOME_VALUE', dateof(now()));

The now function takes no arguments and generates a new unique timeuuid (at the time where the statement using it is executed). The dateOf function takes a timeuuid argument and extracts the embedded timestamp. (Taken from the CQL documentation on timeuuid functions).

Cassandra >= 2.2.0-rc2

dateof() was deprecated in Cassandra 2.2.0-rc2. For later versions you should replace its use with toTimestamp(), as follows:

INSERT INTO TEST (ID, NAME, VALUE, LAST_MODIFIED_DATE)
                  VALUES ('2', 'elephant',  'SOME_VALUE', toTimestamp(now()));

Short & Snazzy:

+ new Date()

A unary operator like plus triggers the valueOf method in the Date object and it returns the timestamp (without any alteration).

Details:

On almost all current browsers you can use Date.now() to get the UTC timestamp in milliseconds; a notable exception to this is IE8 and earlier (see compatibility table).

You can easily make a shim for this, though:

if (!Date.now) {
    Date.now = function() { return new Date().getTime(); }
}

To get the timestamp in seconds, you can use:

Math.floor(Date.now() / 1000)

Or alternatively you could use:

Date.now() / 1000 | 0

Which should be slightly faster, but also less readable.
(also see this answer or this with further explaination to bitwise operators).

I would recommend using Date.now() (with compatibility shim). It's slightly better because it's shorter & doesn't create a new Date object. However, if you don't want a shim & maximum compatibility, you could use the "old" method to get the timestamp in milliseconds:

new Date().getTime()

Which you can then convert to seconds like this:

Math.round(new Date().getTime()/1000)

And you can also use the valueOf method which we showed above:

new Date().valueOf()

Timestamp in Milliseconds

var timeStampInMs = window.performance && window.performance.now && window.performance.timing && window.performance.timing.navigationStart ? window.performance.now() + window.performance.timing.navigationStart : Date.now();

console.log(timeStampInMs, Date.now());

Php – How to insert the current timestamp into MySQL database using a PHP insert query

What error message are you getting?

I'd guess your actual error is because your php variable isn't wrapped in quotes. Try this

$update_query = "UPDATE db.tablename SET insert_time=now() WHERE username='" .$somename . "'";

Best Answer

Cassandra >= 2.2.0-rc2

Related Solutions

Javascript – How to get a timestamp in JavaScript

Short & Snazzy:

Php – How to insert the current timestamp into MySQL database using a PHP insert query

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