expire

expire(key, seconds, callback)

為key對應資料設定seconds秒的效期(Expire Time)，時間超過效期資料自動變空值。

Redis 7.0版本起 EXPIRE 起支援以下參數：

• NX -- Set expiry only when the key has no expiry

• XX -- Set expiry only when the key has an existing expiry

• GT -- Set expiry only when the new expiry is greater than current one

• LT -- Set expiry only when the new expiry is less than current one

A non-volatile key is treated as an infinite TTL for the purpose of GT and LT. The GT, LT and NX options are mutually exclusive.

TypeScript

function delay(ms: number) {
    return new Promise( resolve => setTimeout(resolve, ms) );
}

(async () => { 
    console.log('=== First set and get ===');
    client.set("foo", "bar");
    client.expire("foo", 5); 
    client.get('foo', redis.print); 
    client.ttl('foo', redis.print); 
    
    await delay(5000);
    
    console.log('=== Second get ===');
    client.get('foo', redis.print); 
    client.ttl('foo', redis.print); 
    
    await delay(1000);
    
    console.log('=== Last get ===');
    client.get('foo', redis.print); 
    client.ttl('foo', redis.print); 
})();

Output-TS

=== First set and get ===
Reply: bar
Reply: 5
=== Second get ===
Reply: bar
Reply: 0
=== Last get ===
Reply: null
Reply: -2