[英]Extract data from a dataframe in pyspark
我正在嘗試在 pyspark 中創建一個腳本,它將從表中獲取最小和最大日期將它們存儲在 df 中,然后將這兩個值拆分為 2 個變量,然后將這些變量作為時間范圍放置在另一個查詢中。 我的問題是日期是這樣的數據框
+--------+--------+
| maxDate| minDate|
+--------+--------+
|20210701|20210629|
+--------+--------+
我只想要 maxDate 和 minDate 的值。
我試過dates.iloc[0]
和var1 = dates['maxDate'].values[0]
但它沒有用。
from pyspark.sql import SparkSession
from pyspark.sql.functions import when
from pyspark.sql import functions as F
from pyspark.sql.functions import lit
from pyspark.sql.functions import trim
from datetime import datetime
current_timestamp = datetime.strftime(datetime.now(), "%Y%m%d%H%M")
spark = SparkSession.builder.appName("testing") \
.config("hive.exec.dynamic.partition", "true") \
.config("hive.exec.dynamic.partition.mode", "nonstrict") \
.config("hive.exec.compress.output=false", "false") \
.config("spark.unsafe.sorter.spill.read.ahead.enabled", "false") \
.config("spark.debug.maxToStringFields", 1000)\
.enableHiveSupport() \
.getOrCreate()
spark.sql("set max_row_size = 6mb")
dates = spark.sql("SELECT MAX(date) as maxDate, MIN(date) as minDate FROM db.table")
#dates must be split here in two separated vars
result = spark.sql("select * from db.table_2 where date between {} and {}".format(var1,var2)
你可以像下面這樣
max_date = df.collect()[0][0]
min_date = df.collect()[0][1]
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