CREATE TABLE，采用 Hive 格式

  • 项目

适用于：check marked yes Databricks Runtime

使用 Hive 格式定义表。

语法

CREATE [ EXTERNAL ] TABLE [ IF NOT EXISTS ] table_identifier
    [ ( col_name1[:] col_type1 [ COMMENT col_comment1 ], ... ) ]
    [ COMMENT table_comment ]
    [ PARTITIONED BY ( col_name2[:] col_type2 [ COMMENT col_comment2 ], ... )
        | ( col_name1, col_name2, ... ) ]
    [ ROW FORMAT row_format ]
    [ STORED AS file_format ]
    [ LOCATION path ]
    [ TBLPROPERTIES ( key1=val1, key2=val2, ... ) ]
    [ AS select_statement ]

row_format:
    : SERDE serde_class [ WITH SERDEPROPERTIES (k1=v1, k2=v2, ... ) ]
    | DELIMITED [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escaped_char ] ]
        [ COLLECTION ITEMS TERMINATED BY collection_items_terminated_char ]
        [ MAP KEYS TERMINATED BY map_key_terminated_char ]
        [ LINES TERMINATED BY row_terminated_char ]
        [ NULL DEFINED AS null_char ]

列定义子句和 AS SELECT子句之间的子句可按任意顺序出现。 例如，可在 TBLPROPERTIES 之后写入 COMMENT table_comment。

注意

必须指定 STORED AS 或 ROW FORMAT 子句。 否则，SQL 分析程序会使用 CREATE TABLE USING 语法分析它，并在默认情况下创建一个 Delta 表。

参数

  • table_identifier

    表名，可选择使用架构名称进行限定。

    语法：[schema_name.] table_name

  • EXTERNAL

    使用 LOCATION 中提供的路径定义表。

  • PARTITIONED BY

    请按指定的列对表进行分区。

  • ROW FORMAT

    使用 SERDE 子句为一个表指定自定义 SerDe。 否则，请使用 DELIMITED 子句来使用本机 SerDe，并指定分隔符、转义字符和空字符等。

  • SERDE

    为一个表指定自定义 SerDe。

  • serde_class

    指定自定义 SerDe 的完全限定类名。

  • SERDEPROPERTIES

    用于标记 SerDe 定义的键值对列表。

  • DELIMITED

    可以使用 DELIMITED 子句来指定原生 SerDe，并指明分隔符、转义字符和空字符等。

  • FIELDS TERMINATED BY

    用于定义列分隔符。

  • COLLECTION ITEMS TERMINATED BY

    用于定义收集项分隔符。

  • MAP KEYS TERMINATED BY

    用于定义映射键分隔符。

  • LINES TERMINATED BY

    用于定义行分隔符。

  • NULL DEFINED AS

    用于定义 NULL 的特定值。

  • ESCAPED BY

    定义转义机制。

  • COLLECTION ITEMS TERMINATED BY

    定义收集项分隔符。

  • MAP KEYS TERMINATED BY

    定义映射键分隔符。

  • LINES TERMINATED BY

    定义行分隔符。

  • NULL DEFINED AS

    定义 NULL 的特定值。

  • STORED AS

    此表的文件格式。 可用格式包括 TEXTFILE、SEQUENCEFILE、RCFILE、ORC、PARQUET 和 AVRO。 或者，你可以通过 INPUTFORMAT 和 OUTPUTFORMAT 指定你自己的输入和输出格式。 只能将格式 TEXTFILE、SEQUENCEFILE 和 RCFILE 用于 ROW FORMAT SERDE，并且只能将 TEXTFILE 用于 ROW FORMAT DELIMITED。

  • LOCATION

    用于存储表数据的目录路径，可以是分布式存储上的一个路径。

  • COMMENT

    用于描述表的字符串字面量。

  • TBLPROPERTIES

    用于标记表定义的键值对列表。

  • AS select_statement

    使用 select 语句中的数据填充表。

示例

--Use hive format
CREATE TABLE student (id INT, name STRING, age INT) STORED AS ORC;

--Use data from another table
CREATE TABLE student_copy STORED AS ORC
    AS SELECT * FROM student;

--Specify table comment and properties
CREATE TABLE student (id INT, name STRING, age INT)
    COMMENT 'this is a comment'
    STORED AS ORC
    TBLPROPERTIES ('foo'='bar');

--Specify table comment and properties with different clauses order
CREATE TABLE student (id INT, name STRING, age INT)
    STORED AS ORC
    TBLPROPERTIES ('foo'='bar')
    COMMENT 'this is a comment';

--Create partitioned table
CREATE TABLE student (id INT, name STRING)
    PARTITIONED BY (age INT)
    STORED AS ORC;

--Create partitioned table with different clauses order
CREATE TABLE student (id INT, name STRING)
    STORED AS ORC
    PARTITIONED BY (age INT);

--Use Row Format and file format
CREATE TABLE student (id INT, name STRING)
    ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
    STORED AS TEXTFILE;

--Use complex datatype
CREATE EXTERNAL TABLE family(
        name STRING,
        friends ARRAY<STRING>,
        children MAP<STRING, INT>,
        address STRUCT<street: STRING, city: STRING>
    )
    ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' ESCAPED BY '\\'
    COLLECTION ITEMS TERMINATED BY '_'
    MAP KEYS TERMINATED BY ':'
    LINES TERMINATED BY '\n'
    NULL DEFINED AS 'foonull'
    STORED AS TEXTFILE
    LOCATION '/tmp/family/';

--Use predefined custom SerDe
CREATE TABLE avroExample
    ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.avro.AvroSerDe'
    STORED AS INPUTFORMAT 'org.apache.hadoop.hive.ql.io.avro.AvroContainerInputFormat'
        OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.avro.AvroContainerOutputFormat'
    TBLPROPERTIES ('avro.schema.literal'='{ "namespace": "org.apache.hive",
        "name": "first_schema",
        "type": "record",
        "fields": [
                { "name":"string1", "type":"string" },
                { "name":"string2", "type":"string" }
            ] }');

--Use personalized custom SerDe(we may need to `ADD JAR xxx.jar` first to ensure we can find the serde_class,
--or you may run into `CLASSNOTFOUND` exception)
ADD JAR /tmp/hive_serde_example.jar;

CREATE EXTERNAL TABLE family (id INT, name STRING)
    ROW FORMAT SERDE 'com.ly.spark.serde.SerDeExample'
    STORED AS INPUTFORMAT 'com.ly.spark.example.serde.io.SerDeExampleInputFormat'
        OUTPUTFORMAT 'com.ly.spark.example.serde.io.SerDeExampleOutputFormat'
    LOCATION '/tmp/family/';