订阅你的数据库中的实时变化。

  supabase.channel('*').on(
  RealtimeListenTypes.postgresChanges,
  ChannelFilter(event: '*', schema: '*'),
  (payload, [ref]) {
    print('Change received: ${payload.toString()}');
  },
).subscribe();

Notes

  • 为了提高数据库性能和安全性，新项目的实时性默认是禁用的。你可以通过管理复制打开它。
  • 如果你想在更新和删除时接收 “以前的"数据，你需要将REPLICA IDENTITY设置为FULL，像这样。ALTER TABLE your_table REPLICA IDENTITY FULL;。

Examples

监听所有的数据库变化 

  supabase.channel('*').on(
  RealtimeListenTypes.postgresChanges,
  ChannelFilter(event: '*', schema: '*'),
  (payload, [ref]) {
    print('Change received: ${payload.toString()}');
  },
).subscribe();

监听一个特定的表 

  supabase.channel('public:countries').on(
  RealtimeListenTypes.postgresChanges,
  ChannelFilter(event: '*', schema: 'public', table: 'countries'),
  (payload, [ref]) {
    print('Change received: ${payload.toString()}');
  },
).subscribe();

监听插入 

  supabase.channel('public:countries').on(
  RealtimeListenTypes.postgresChanges,
  ChannelFilter(event: 'INSERT', schema: 'public', table: 'countries'),
  (payload, [ref]) {
    print('Change received: ${payload.toString()}');
  },
).subscribe();

监听修改

默认情况下，Supabase 将只发送更新的记录。如果你想同时接收以前的值，你可以 为你监听的表启用完全复制。

  alter table "your_table" replica identity full;
  
  supabase.channel('public:countries').on(
  RealtimeListenTypes.postgresChanges,
  ChannelFilter(event: 'UPDATE', schema: 'public', table: 'countries'),
  (payload, [ref]) {
    print('Change received: ${payload.toString()}');
  },
).subscribe();

监听删除

默认情况下，Supabase 不发送已删除的记录。如果你想接收删除的记录，你可以 为你所监听的表启用完全复制功能。

  alter table "your_table" replica identity full;
  
  supabase.channel('public:countries').on(
  RealtimeListenTypes.postgresChanges,
  ChannelFilter(event: 'DELETE', schema: 'public', table: 'countries'),
  (payload, [ref]) {
    print('Change received: ${payload.toString()}');
  },
).subscribe();

监听多个事件

如果你想监听每个表的多个事件，你可以用链式监听器。

  supabase.channel('public:countries').on(RealtimeListenTypes.postgresChanges,
    ChannelFilter(event: 'INSERT', schema: 'public', table: 'countries'),
    (payload, [ref]) {
  print('Change received: ${payload.toString()}');
}).on(RealtimeListenTypes.postgresChanges,
    ChannelFilter(event: 'DELETE', schema: 'public', table: 'countries'),
    (payload, [ref]) {
  print('Change received: ${payload.toString()}');
}).subscribe();

监听行级变化

你可以使用{table}:{col}=eq.{val}的格式来监听单个行，其中{col}是列名，{val}是你想要匹配的值。

  supabase.channel('public:countries:id=eq.200').on(
    RealtimeListenTypes.postgresChanges,
    ChannelFilter(
      event: 'UPDATE',
      schema: 'public',
      table: 'countries',
      filter: 'id=eq.200',
    ), (payload, [ref]) {
  print('Change received: ${payload.toString()}');
}).subscribe();