数组中列的PHP唯一值

时间：2013-01-11 01:24:10

标签： php arrays unique

我有一个从我运行的SQL查询生成的数组。它看起来如下：

$arr[$i]['id'] = $id;
$arr[$i]['name'] = $name;
$arr[$i]['email'] = $email;

如何从电子邮件列中获取唯一值？我很感激帮助。

5 个答案:

答案 0 :(得分：8)

使用MySQL中的DISTINCT方法在列中过滤它，或使用类似

的方法 
$uniqueEmails = array();
foreach($arr as $array)
{
    if(!in_array($array['email'], $uniqueEmails)
        $uniqueEmails[] = $array['email'];
}

答案 1 :(得分：5)

自PHP 5.5起，还可以使用名为array_column()的新函数。 您可以按照以下方式使用它：

$allEmails = array_column($arr, 'email');
$uniqueEmails = array_unique($allEmails);

答案 2 :(得分：0)

如果您通过电子邮件从SQL获取列表，则可以通过像Gareth那样循环遍历数组来提高性能，而只是将当前电子邮件地址与上次插入的电子邮件地址进行比较。下面是一个代码示例：

$uniqueEmails = array();
$lastemail = '';
foreach($arr as $array)
{
    if($array['email'] != $lastemail)
    {
        $uniqueEmails[] = $array['email'];
        $lastemail = $array['email'];
    }
}

答案 3 :(得分：0)

最佳答案是：

java.net.UnknownHostException: zk0-apache.xxxxxxxxxxxxxxxxxxxxxxxxx.tx.internal.cloudapp.net: nodename nor servname provided, or not known
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method) ~[na:1.8.0_172]
at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928) ~[na:1.8.0_172]
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323) ~[na:1.8.0_172]
at java.net.InetAddress.getAllByName0(InetAddress.java:1276) ~[na:1.8.0_172]
at java.net.InetAddress.getAllByName(InetAddress.java:1192) ~[na:1.8.0_172]
at java.net.InetAddress.getAllByName(InetAddress.java:1126) ~[na:1.8.0_172]
at org.apache.zookeeper.client.StaticHostProvider.<init>(StaticHostProvider.java:61) ~[zookeeper-3.4.10.jar:3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f]
at org.apache.zookeeper.ZooKeeper.<init>(ZooKeeper.java:445) ~[zookeeper-3.4.10.jar:3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f]
at org.apache.zookeeper.ZooKeeper.<init>(ZooKeeper.java:380) ~[zookeeper-3.4.10.jar:3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f]
at org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper.checkZk(RecoverableZooKeeper.java:144) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper.<init>(RecoverableZooKeeper.java:131) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.zookeeper.ZKUtil.connect(ZKUtil.java:143) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.<init>(ZooKeeperWatcher.java:181) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.<init>(ZooKeeperWatcher.java:155) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.ZooKeeperKeepAliveConnection.<init>(ZooKeeperKeepAliveConnection.java:43) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.getKeepAliveZooKeeperWatcher(ConnectionManager.java:1737) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.ZooKeeperRegistry.getClusterId(ZooKeeperRegistry.java:104) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.retrieveClusterId(ConnectionManager.java:945) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.<init>(ConnectionManager.java:721) [hbase-client-1.4.0.jar:1.4.0]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) [na:1.8.0_172]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) [na:1.8.0_172]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) [na:1.8.0_172]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) [na:1.8.0_172]
at org.apache.hadoop.hbase.client.ConnectionFactory.createConnection(ConnectionFactory.java:238) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.ConnectionManager.createConnection(ConnectionManager.java:439) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.ConnectionManager.createConnectionInternal(ConnectionManager.java:348) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.hadoop.hbase.client.HConnectionManager.createConnection(HConnectionManager.java:144) [hbase-client-1.4.0.jar:1.4.0]
at org.apache.phoenix.query.HConnectionFactory$HConnectionFactoryImpl.createConnection(HConnectionFactory.java:47) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.query.ConnectionQueryServicesImpl.openConnection(ConnectionQueryServicesImpl.java:425) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.query.ConnectionQueryServicesImpl.access$400(ConnectionQueryServicesImpl.java:267) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.query.ConnectionQueryServicesImpl$12.call(ConnectionQueryServicesImpl.java:2515) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.query.ConnectionQueryServicesImpl$12.call(ConnectionQueryServicesImpl.java:2491) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.util.PhoenixContextExecutor.call(PhoenixContextExecutor.java:76) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.query.ConnectionQueryServicesImpl.init(ConnectionQueryServicesImpl.java:2491) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.jdbc.PhoenixDriver.getConnectionQueryServices(PhoenixDriver.java:255) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.jdbc.PhoenixEmbeddedDriver.createConnection(PhoenixEmbeddedDriver.java:150) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at org.apache.phoenix.jdbc.PhoenixDriver.connect(PhoenixDriver.java:221) [phoenix-core-4.14.0-HBase-1.4.jar:4.14.0-HBase-1.4]
at java.sql.DriverManager.getConnection(DriverManager.java:664) [na:1.8.0_172]
at java.sql.DriverManager.getConnection(DriverManager.java:208) [na:1.8.0_172]
at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:154) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:145) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:205) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:169) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:324) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.boot.jdbc.EmbeddedDatabaseConnection.isEmbedded(EmbeddedDatabaseConnection.java:123) [spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.jdbc.AbstractDataSourceInitializer.isEnabled(AbstractDataSourceInitializer.java:74) [spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.jdbc.AbstractDataSourceInitializer.initialize(AbstractDataSourceInitializer.java:54) [spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_172]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_172]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_172]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_172]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:419) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1737) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:576) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:846) ~[spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:863) ~[spring-context-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546) ~[spring-context-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at com.myntra.asn_api.AsnApiApplication.main(AsnApiApplication.java:14) ~[classes/:na]

答案 4 :(得分：0)

通过比较特定键从阵列中删除重复项

考虑相同的数组，但第三个索引的id不同：

$all_array = 

Array
(
    [0] => Array
        (
            [id] => 1
            [value] => 111
        )

    [1] => Array
        (
            [id] => 2
            [value] => 222
        )

    [2] => Array
        (
            [id] => 3
            [value] => 333
        )

    [3] => Array
        (
            [id] => 4
            [value] => 111
        )

)

现在，1和4都具有相同的值。因此，我们要删除其中的任何一个。

$unique_arr = array_unique(array_column($all_array , 'value'));
print_r(array_intersect_key($all_array , $unique_arr));
相关问题
最新问题