I want to select a random id from table nodes
from last 15 seconds.
I have tried this but it gives a long output: the code:
const mysql = require('mysql');
const connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: 'password',
database: 'DAGtest3'
});
connection.connect((err) => {
if (err) throw err;
console.log('Database Connected!');
});
var b = connection.query("SELECT t.`id` FROM `nodes` AS t
INNER JOIN (SELECT ROUND( RAND() * (SELECT MAX(id) FROM `nodes` )) AS id ) AS x
WHERE t.id >= x.id AND created_at < DATE_SUB(NOW(), INTERVAL 15 SECOND) LIMIT 1");
console.log(b);
output
Query {
_events: [Object: null prototype] {
error: [Function],
packet: [Function],
timeout: [Function],
end: [Function]
},
_eventsCount: 4,
_maxListeners: undefined,
_callback: undefined,
_callSite: Error
at Protocol._enqueue (/home/istabraq/DAGsim/node_modules/mysql/lib/protocol/Protocol.js:144:48)
at Connection.query (/home/istabraq/DAGsim/node_modules/mysql/lib/Connection.js:198:25)
at Object.<anonymous> (/home/istabraq/DAGsim/test30.js:15:20)
at Module._compile (internal/modules/cjs/loader.js:999:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
at Module.load (internal/modules/cjs/loader.js:863:32)
at Function.Module._load (internal/modules/cjs/loader.js:708:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12)
at internal/main/run_main_module.js:17:47,
_ended: false,
_timeout: undefined,
_timer: Timer { _object: [Circular], _timeout: null },
sql: 'SELECT t.`id` FROM `nodes` AS t INNER JOIN (SELECT ROUND( RAND() * (SELECT MAX(id) FROM `nodes` )) AS id ) AS x WHERE t.id >= x.id AND created_at < DATE_SUB(NOW(), INTERVAL 15 SECOND) LIMIT 1',
values: undefined,
typeCast: true,
nestTables: false,
_resultSet: null,
_results: [],
_fields: [],
_index: 0,
_loadError: null,
_connection: Connection {
_events: [Object: null prototype] {},
_eventsCount: 0,
_maxListeners: undefined,
config: ConnectionConfig {
host: 'localhost',
port: 3306,
localAddress: undefined,
socketPath: undefined,
user: 'root',
password: 'password',
database: 'DAGtest3',
connectTimeout: 10000,
insecureAuth: false,
supportBigNumbers: false,
bigNumberStrings: false,
dateStrings: false,
debug: undefined,
trace: true,
stringifyObjects: false,
timezone: 'local',
flags: '',
queryFormat: undefined,
pool: undefined,
ssl: false,
localInfile: true,
multipleStatements: false,
typeCast: true,
maxPacketSize: 0,
charsetNumber: 33,
clientFlags: 455631
},
_socket: Socket {
connecting: true,
_hadError: false,
_parent: null,
_host: 'localhost',
_readableState: [ReadableState],
readable: false,
_events: [Object: null prototype],
_eventsCount: 5,
_maxListeners: undefined,
_writableState: [WritableState],
writable: true,
allowHalfOpen: false,
_sockname: null,
_pendingData: null,
_pendingEncoding: '',
server: null,
_server: null,
timeout: 10000,
[Symbol(asyncId)]: 2,
[Symbol(kHandle)]: [TCP],
[Symbol(kSetNoDelay)]: false,
[Symbol(lastWriteQueueSize)]: 0,
[Symbol(timeout)]: Timeout {
_idleTimeout: 10000,
_idlePrev: [TimersList],
_idleNext: [TimersList],
_idleStart: 99,
_onTimeout: [Function: bound ],
_timerArgs: undefined,
_repeat: null,
_destroyed: false,
[Symbol(refed)]: false,
[Symbol(kHasPrimitive)]: false,
[Symbol(asyncId)]: 6,
[Symbol(triggerId)]: 1
},
[Symbol(kBuffer)]: null,
[Symbol(kBufferCb)]: null,
[Symbol(kBufferGen)]: null,
[Symbol(kCapture)]: false,
[Symbol(kBytesRead)]: 0,
[Symbol(kBytesWritten)]: 0
},
_protocol: Protocol {
_events: [Object: null prototype],
_eventsCount: 7,
_maxListeners: undefined,
readable: true,
writable: true,
_config: [ConnectionConfig],
_connection: [Circular],
_callback: null,
_fatalError: null,
_quitSequence: null,
_handshake: true,
_handshaked: false,
_ended: false,
_destroyed: false,
_queue: [Array],
_handshakeInitializationPacket: null,
_parser: [Parser],
[Symbol(kCapture)]: false
},
_connectCalled: true,
state: 'disconnected',
threadId: null,
[Symbol(kCapture)]: false
},
[Symbol(kCapture)]: false
}
How to solve it, please?
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