Why does Spark SQL require double percent symbols for like conditions? - apache-spark

Question

When I am using a like condition in Spark SQL, it seems that it requires the use of 2 percent symbols %%.
However, I could not find any documentation on this in the Spark SQL docs. I am curious as to why my set-up might be causing this requirement.
https://spark.apache.org/docs/3.3.0/sql-ref-syntax-qry-select-like.html
Example data
product_table
id
product_type
region
location
measurement
43635665
ORANGE - Blood Orange
EU
FRA
30.5
78960788
APPLE GrannySmith
NA
USA
16.0
12312343
APPLE [Organic Washington]
NA
CAN
7.1
67867634
ORANGE, NavelOrange
NA
MEX
88.4
import pyspark
from pyspark.sql import functions as F
APP_NAME = "Product: Fruit Template"
SPARK_CONF = [
("spark.dynamicAllocation.maxExecutors", "5"),
("spark.executor.memory", "10g"),
("spark.executor.cores", "4"),
("spark.executor.memoryOverhead", "2000"),
]
spark_conf = pyspark.SparkConf()
spark_conf.setAppName(APP_NAME)
spark_conf.setAll(SPARK_CONF)
sc = pyspark.SparkContext(conf=spark_conf)
spark = pyspark.sql.SparkSession(sc)
def sql(query):
return spark.sql(query)
df = sql("""
SELECT *
FROM product_table
""")
this returns data
df.filter(F.col("product_type").like("ORANGE%%")).show()
whereas this returns an empty dataframe
df.filter(F.col("product_type").like("ORANGE%")).show()
Maybe worth noting, the same issue happens when the LIKE condition is used in the SQL string
this returns data
df_new = sql("""
SELECT *
FROM product_table
WHERE product_type like 'ORANGE%%'
""")
df_new.show()
whereas this returns an empty dataframe
df_new = sql("""
SELECT *
FROM product_table
WHERE product_type like 'ORANGE%'
""")
df_new.show()

Answer 1

i am using PySpark Version: 2.3.2.
conf = (SparkConf()
.set("spark.executor.instances", "24")
.set("spark.executor.cores", "5")
.set("spark.executor.memory", "33g")
.set("spark.driver.memory", "55g")
.set("spark.driver.maxResultSize", "10g")
.set("spark.sql.catalogImplementation", "hive")
.set("mapreduce.fileoutputcommitter.algorithm.version", "2")
)
spark = (
SparkSession.builder.appName("default")
.enableHiveSupport()
.config(conf=conf)
.getOrCreate()
)
df = spark.createDataFrame(
[('43635665','ORANGE - Blood Orange'),
('78960788','APPLE GrannySmith'),
('12312343','APPLE [Organic Washington'),
('67867634','ORANGE, NavelOrange')],
['id', 'product_type'])
df.createOrReplaceTempView("product_table")
def sql(query):
print(query)
return spark.sql(query)
df2 = sql("""
SELECT *
FROM product_table
""")
df2.filter(F.col("product_type").like("ORANGE%")).show(truncate=False)