In Hive, the process for storing and accessing a Map with key-value pairs of String data type involves the following steps:
For example, to create a table with a Map column in Hive:
CREATE TABLE mytable (id INT, mymap MAP<STRING, STRING>);
To insert data into the table:
INSERT INTO mytable VALUES (1, map('key1', 'value1', 'key2', 'value2'));
To query the data:
SELECT id, mymap['key1'] FROM mytable WHERE id = 1;
In Spark, the process is similar:
For example, to create a DataFrame with a Map column in Spark:
val mydf = Seq((1, Map("key1" -> "value1", "key2" -> "value2"))).toDF("id", "mymap")
To query the data:
mydf.select($"id", $"mymap"("key1")).where($"id" === 1).show()
Asked: 2022-04-23 11:00:00 +0000
Seen: 19 times
Last updated: Oct 27 '21