我正在尝试在postgresql中存储具有嵌套模式的Dataframe。有人能帮我解释一下如何在postgres中存储列(坐标)和(用户提到的)?我读到postgres可以存储数组类型,但在尝试写入db时出现了一个错误。我不完全确定我的表是否创建正确。
错误:
Exception in thread "main" java.lang.IllegalArgumentException: Can't get JDBC type for array<array<double>>
Dataframe架构:
root
|-- created_at: string (nullable = true)
|-- id: long (nullable = true)
|-- text: string (nullable = true)
|-- source: string (nullable = true)
|-- user_id: long (nullable = true)
|-- in_reply_to_status_id: string (nullable = true)
|-- in_reply_to_user_id: long (nullable = true)
|-- lang: string (nullable = true)
|-- retweet_count: long (nullable = true)
|-- reply_count: long (nullable = true)
|-- coordinates: array (nullable = true)
| |-- element: array (containsNull = true)
| | |-- element: double (containsNull = true)
|-- hashtags: array (nullable = true)
| |-- element: string (containsNull = true)
|-- user_mentions: array (nullable = true)
| |-- element: struct (containsNull = true)
| | |-- id: long (nullable = true)
| | |-- id_str: string (nullable = true)
| | |-- indices: array (nullable = true)
| | | |-- element: long (containsNull = true)
| | |-- name: string (nullable = true)
| | |-- screen_name: string (nullable = true)
postgres表创建:
create table test-table (created_at varchar, id int, text text, source text, user_id int, in_reply_to_status_id varchar, in_reply_to_user_id int, lang varchar, retweet_count int, reply_count int, coordinates double precision[][], hashtags text[], user_mentions text[]);
spark scala代码:
val df_1 = df.select(col("created_at"), col("id"), col("text"), col("source"), col("user.id").as("user_id"),
col("in_reply_to_status_id"), col("in_reply_to_user_id"),
col("lang"), col("retweet_count"), col("reply_count"), col("place.bounding_box.coordinates"),
col("entities.hashtags"), col("entities.user_mentions")).withColumn("coordinates", explode(col("coordinates")))
df_1.show(truncate = false)
df_1.printSchema()
df_1.write
.format("jdbc")
.option("url", "postgres_url")
.option("dbtable", "xxx.mytable")
.option("user", "user")
.option("password", "pass")
.save()
样本输入:
坐标列:
[[80.063341, 26.348309], [80.063341, 30.43339], [88.2027, 30.43339], [88.2027, 26.348309]]
用户提到:
[[123456789, 123456789, [0, 15], Name, ScreenName]]
1条答案
按热度按时间rjee0c151#
spark只支持用jdbc读写一维数组。您可以将数据转换为具有多行(即。
explode
它必须在多行中有double[]),或者您可以从中转换数据double[][]
以逗号分隔string[]
或者普通的string
.例如。
[[1, 2], [3, 4]]
可以转换为["1,2", "3,4"]