将pyspark dataframe写入Postgres，而不将列标记为非空

from pyspark.sql import SparkSession
from pyspark.sql.types import *

spark = SparkSession.builder \
    .appName("Write DataFrame to Postgres") \
    .getOrCreate()

postgres_url = "jdbc:postgresql://<host>:<port>/<database>"
postgres_properties = {
    "user": "<username>",
    "password": "<password>",
    "driver": "org.postgresql.Driver"
}

data = [("Alice", 25), ("Bob", 30), ("Charlie", 35)]
schema = StructType([
    StructField("name", StringType(), nullable=False),
    StructField("age", IntegerType(), nullable=True)
])
df = spark.createDataFrame(data, schema)

df.write \
    .format("jdbc") \
    .option("url", postgres_url) \
    .option("dbtable", "<table_name>") \
    .mode("overwrite") \
    .options(**postgres_properties) \
    .save()