CREATE-EXTERNAL-TABLE

Name

CREATE EXTERNAL TABLE

Description

This statement is used to create an external table, see CREATE TABLE for the specific syntax.

Which type of external table is mainly identified by the ENGINE type, currently MYSQL, BROKER, HIVE, ICEBERG, HUDI are optional

1. If it is mysql, you need to provide the following information in properties:

   PROPERTIES (
   "host" = "mysql_server_host",
   "port" = "mysql_server_port",
   "user" = "your_user_name",
   "password" = "your_password",
   "database" = "database_name",
   "table" = "table_name"
   )

   and there is an optional propertiy “charset” which can set character fom mysql connection, default value is “utf8”. You can set another value “utf8mb4” instead of “utf8” when you need.

   Notice:

   • “table_name” in “table” entry is the real table name in mysql. The table_name in the CREATE TABLE statement is the name of the mysql table in Doris, which can be different.

   • The purpose of creating a mysql table in Doris is to access the mysql database through Doris. Doris itself does not maintain or store any mysql data.

2. If it is a broker, it means that the access to the table needs to pass through the specified broker, and the following information needs to be provided in properties:

   PROPERTIES (
   "broker_name" = "broker_name",
   "path" = "file_path1[,file_path2]",
   "column_separator" = "value_separator"
   "line_delimiter" = "value_delimiter"
   )

   In addition, you need to provide the Property information required by the Broker, and pass it through the BROKER PROPERTIES, for example, HDFS needs to pass in

   BROKER PROPERTIES(
     "username" = "name",
     "password" = "password"
   )

   According to different Broker types, the content that needs to be passed in is also different.

   Notice:

   • If there are multiple files in “path”, separate them with comma [,]. If the filename contains a comma, use %2c instead. If the filename contains %, use %25 instead
   • Now the file content format supports CSV, and supports GZ, BZ2, LZ4, LZO (LZOP) compression formats.

3. If it is hive, you need to provide the following information in properties:

   PROPERTIES (
   "database" = "hive_db_name",
   "table" = "hive_table_name",
   "hive.metastore.uris" = "thrift://127.0.0.1:9083"
   )

   Where database is the name of the library corresponding to the hive table, table is the name of the hive table, and hive.metastore.uris is the address of the hive metastore service.

4. In case of iceberg, you need to provide the following information in properties:

   PROPERTIES (
   "iceberg.database" = "iceberg_db_name",
   "iceberg.table" = "iceberg_table_name",
   "iceberg.hive.metastore.uris" = "thrift://127.0.0.1:9083",
   "iceberg.catalog.type" = "HIVE_CATALOG"
   )

   Where database is the library name corresponding to Iceberg; table is the corresponding table name in Iceberg; hive.metastore.uris is the hive metastore service address; catalog.type defaults to HIVE_CATALOG. Currently only HIVE_CATALOG is supported, more Iceberg catalog types will be supported in the future.

5. In case of hudi, you need to provide the following information in properties:

   PROPERTIES (
   "hudi.database" = "hudi_db_in_hive_metastore",
   "hudi.table" = "hudi_table_in_hive_metastore",
   "hudi.hive.metastore.uris" = "thrift://127.0.0.1:9083"
   )

   Where hudi.database is the corresponding database name in HiveMetaStore; hudi.table is the corresponding table name in HiveMetaStore; hive.metastore.uris is the hive metastore service address;

Example

1. Create a MYSQL external table

   Create mysql table directly from outer table information

   CREATE EXTERNAL TABLE example_db.table_mysql
   (
   k1 DATE,
   k2 INT,
   k3 SMALLINT,
   k4 VARCHAR(2048),
   k5 DATETIME
   )
   ENGINE=mysql
   PROPERTIES
   (
   "host" = "127.0.0.1",
   "port" = "8239",
   "user" = "mysql_user",
   "password" = "mysql_passwd",
   "database" = "mysql_db_test",
   "table" = "mysql_table_test",
   "charset" = "utf8mb4"
   )

   Create mysql table through External Catalog Resource

   # Create Resource first
   CREATE EXTERNAL RESOURCE "mysql_resource"
   PROPERTIES
   (
     "type" = "odbc_catalog",
     "user" = "mysql_user",
     "password" = "mysql_passwd",
     "host" = "127.0.0.1",
      "port" = "8239"
   );
   # Then create mysql external table through Resource
   CREATE EXTERNAL TABLE example_db.table_mysql
   (
   k1 DATE,
   k2 INT,
   k3 SMALLINT,
   k4 VARCHAR(2048),
   k5 DATETIME
   )
   ENGINE=mysql
   PROPERTIES
   (
   "odbc_catalog_resource" = "mysql_resource",
   "database" = "mysql_db_test",
   "table" = "mysql_table_test"
   )

2. Create a broker external table with data files stored on HDFS, the data is split with “|”, and “\n” is newline

   CREATE EXTERNAL TABLE example_db.table_broker (
   k1 DATE,
   k2 INT,
   k3 SMALLINT,
   k4 VARCHAR(2048),
   k5 DATETIME
   )
   ENGINE=broker
   PROPERTIES (
   "broker_name" = "hdfs",
   "path" = "hdfs://hdfs_host:hdfs_port/data1,hdfs://hdfs_host:hdfs_port/data2,hdfs://hdfs_host:hdfs_port/data3%2c4",
   "column_separator" = "|",
   "line_delimiter" = "\n"
   )
   BROKER PROPERTIES (
   "username" = "hdfs_user",
   "password" = "hdfs_password"
   )

3. Create a hive external table

   CREATE TABLE example_db.table_hive
   (
     k1 TINYINT,
     k2 VARCHAR(50),
     v INT
   )
   ENGINE=hive
   PROPERTIES
   (
     "database" = "hive_db_name",
     "table" = "hive_table_name",
     "hive.metastore.uris" = "thrift://127.0.0.1:9083"
   );

4. Create an Iceberg skin

   CREATE TABLE example_db.t_iceberg
   ENGINE=ICEBERG
   PROPERTIES (
   "iceberg.database" = "iceberg_db",
   "iceberg.table" = "iceberg_table",
   "iceberg.hive.metastore.uris" = "thrift://127.0.0.1:9083",
   "iceberg.catalog.type" = "HIVE_CATALOG"
   );

5. Create an Hudi external table

   create hudi table without schema(recommend)

   CREATE TABLE example_db.t_hudi
   ENGINE=HUDI
   PROPERTIES (
   "hudi.database" = "hudi_db_in_hive_metastore",
   "hudi.table" = "hudi_table_in_hive_metastore",
   "hudi.hive.metastore.uris" = "thrift://127.0.0.1:9083"
   );

   create hudi table with schema

   CREATE TABLE example_db.t_hudi (
      `id` int NOT NULL COMMENT "id number",
      `name` varchar(10) NOT NULL COMMENT "user name"
   )
   ENGINE=HUDI
   PROPERTIES (
   "hudi.database" = "hudi_db_in_hive_metastore",
   "hudi.table" = "hudi_table_in_hive_metastore",
   "hudi.hive.metastore.uris" = "thrift://127.0.0.1:9083"
   );

Keywords

CREATE, EXTERNAL, TABLE

Best Practice