Task: Generate and insert data into a Postgres database

n8n workflow JSON:
{"id":"33","name":"Postgres Data Ingestion","nodes":[{"name":"Cron","type":"n8n-nodes-base.cron","position":[300,250],"parameters":{"triggerTimes":{"item":[{"mode":"everyMinute"}]}},"typeVersion":1},{"name":"Function","type":"n8n-nodes-base.function","position":[500,250],"parameters":{"functionCode":"var today = new Date();\nvar date = today.getFullYear()+'-'+(today.getMonth()+1)+'-'+today.getDate();\nvar time = today.getHours() + \":\" + today.getMinutes() + \":\" + today.getSeconds();\nvar dateTime = date+' '+time;\n\nitems[0].json.sensor_id = 'humidity01';\nitems[0].json.value = Math.ceil(Math.random()*100);\nitems[0].json.time_stamp = dateTime;\nitems[0].json.notification = false;\n\nreturn items;"},"typeVersion":1},{"name":"Postgres","type":"n8n-nodes-base.postgres","position":[680,250],"parameters":{"table":"n8n","columns":"sensor_id,value,time_stamp,notification"},"credentials":{"postgres":"Postgres"},"typeVersion":1}],"active":true,"settings":{},"connections":{"Cron":{"main":[[{"node":"Function","type":"main","index":0}]]},"Function":{"main":[[{"node":"Postgres","type":"main","index":0}]]}}}