Question

我正在使用MYSQL数据库中的PHP创建一个简单的CSV文件。

CSV文件创建得很好，内容就在他们需要的位置，但CSV文件没有任何标题！

这个我的代码：

<?php 
    header('Content-Type: text/csv; charset=utf-8');
    header('Content-Disposition: attachment; filename=data.csv');

    $output = fopen('php://output', 'w');

    $rows = mysqli_query($db_conx, 'SELECT u.email as referrer, 
                                        ref.email as referred 
                                    from users u 
                                        INNER JOIN users ref 
                                            on u.ref_code=ref.ref_code_used');

    while ($row = mysqli_fetch_assoc($rows)) {


      fputcsv($output, $row);
    }
    fclose($output);
    mysqli_close($db_conx);
    exit();

?>

CSV的标题应为referrer和referred ...我认为这样做会：

SELECT u.email as referrer, ref.email as referred from users u INNER JOIN users ref on u.ref_code=ref.ref_code_used

但是这并没有将标题放在CSV文件中。

有人可以就此问题提出建议吗？

提前致谢。

Answer 1

这样的事情怎么样？首先，我们检查您是否有输出标头。如果没有，请使用array_keys函数打印标题。

$headers = false;

while ($row = mysqli_fetch_assoc($rows)) {

  if (!$headers) {
    fputcsv($output, array_keys($row));
    $headers = true;
  }

  fputcsv($output, $row);
}

Answer 2

这对我来说很好：

R version 3.4.1 (2017-06-30) -- "Single Candle"
Copyright (C) 2017 The R Foundation for Statistical Computing
Platform: x86_64-redhat-linux-gnu (64-bit)

[Previously saved workspace restored]

> Sys.info()['nodename']
nodename 
"econ14" 
> 
> #memory.limit(size=10000)
> 
> #options(java.parameters = "-Xmx8048m")
> 
> 
> rm(list = ls()) #clear database
> library("sparklyr",lib.loc="/econ_s/saraiva/R_libs")
> library(dplyr,lib.loc="/econ_s/saraiva/R_libs")

Attaching package: ‘dplyr’

The following objects are masked from ‘package:stats’:

    filter, lag

The following objects are masked from ‘package:base’:

    intersect, setdiff, setequal, union

> library("config",lib.loc="/econ_s/saraiva/R_libs")#

Attaching package: ‘config’

The following objects are masked from ‘package:base’:

    get, merge

> library("rappdirs",lib.loc="/econ_s/saraiva/R_libs")#
> library("withr",lib.loc="/econ_s/saraiva/R_libs")#
> library("bindrcpp",lib.loc="/econ_s/saraiva/R_libs")#
> 
> 
> #Sys.setenv("SPARK_MEM" = "20g")
> config <- spark_config()
> #config[["sparklyr.shell.conf"]] <- "spark.driver.extraJavaOptions=-XX:MaxHeapSize=24G"
> config$`sparklyr.shell.driver-memory` <- "10G"
> config$`sparklyr.shell.executor-memory` <- "10G"
> config$`spark.driver.maxResultSize` <- "10g"
> config$`spark.yarn.executor.memoryOverhead` <- "16g"
> 
> 
> 
> sc<-spark_connect(master = "local",config = config)
* Using Spark: 2.1.0
> 
> 
> 
> 
> test=spark_read_json(sc = sc, name = "videos", path = "file/path.json")
> 
> #=====Select a subset of variables:=====
> a<-select(test, asin, helpful,overall)#works
> 
> #=====Filter Variables:=================
>a<- filter(test, asin=='B000H0X79O')#works
> #Using a function not defined in dplyr: (causes computer to run out of memory)
> tr<-select(test,  reviewText)
> tr<-pull(tr)
Error: java.lang.OutOfMemoryError: Java heap space
    at java.util.Arrays.copyOf(Arrays.java:2367)
    at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:130)
    at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:114)
    at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:415)
    at java.lang.StringBuilder.append(StringBuilder.java:132)
    at scala.collection.mutable.StringBuilder.append(StringBuilder.scala:200)
    at scala.collection.TraversableOnce$$anonfun$addString$1.apply(TraversableOnce.scala:364)
    at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
    at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:186)
    at scala.collection.TraversableOnce$class.addString(TraversableOnce.scala:357)
    at scala.collection.mutable.ArrayOps$ofRef.addString(ArrayOps.scala:186)
    at scala.collection.TraversableOnce$class.mkString(TraversableOnce.scala:323)
    at scala.collection.mutable.ArrayOps$ofRef.mkString(ArrayOps.scala:186)
    at scala.collection.TraversableOnce$class.mkString(TraversableOnce.scala:325)
    at scala.collection.mutable.ArrayOps$ofRef.mkString(ArrayOps.scala:186)
    at sparklyr.Utils$.collectImplString(utils.scala:136)
    at sparklyr.Utils$.collectImpl(utils.scala:174)
    at sparklyr.Utils$$anonfun$collect$1.apply(utils.scala:198)
    at sparklyr.Utils$$anonfun$collect$1.apply(utils.scala:198)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
    at scala.collection.immutable.Range.foreach(Range.scala:160)
    at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
    at scala.collection.AbstractTraversable.map(Traversable.scala:104)
    at sparklyr.Utils$.collect(utils.scala:198)
    at sparklyr.Utils.collect(utils.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at sparklyr.Invoke$.invoke(invoke.scala:102)
    at sparklyr.StreamHandler$.handleMethodCall(stream.scala:97)
Execution halted

PHP：生成的CSV文件没有任何标题？

2 个答案: