hequn8128 commented on a change in pull request #9886:
[FLINK-14027][python][doc] Add documentation for Python user-defined functions.
URL: https://github.com/apache/flink/pull/9886#discussion_r334384504
##########
File path: docs/dev/table/udfs.md
##########
@@ -112,50 +152,54 @@ public class HashCode extends ScalarFunction {
}
'''
+class HashCode(ScalarFunction):
+ def eval(self, s):
+ return hash(s) * factor
+
table_env = BatchTableEnvironment.create(env)
-# register the java function
+# register the Java function
table_env.register_java_function("hashCode", "my.java.function.HashCode")
+# register the Python function
+table_env.register_function("py_hash_code", udf(HashCode(),
DataTypes.STRING(), DataTypes.BIGINT()))
+
# use the function in Python Table API
-my_table.select("string, string.hashCode(), hashCode(string)")
+my_table.select("string, string.hashCode(), hashCode(string),
string.py_hash_code(), py_hash_code(string)")
Review comment:
String type has not been supported by now for the python udfs. We can use
bigint for now and change to string later.
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