Schema Export

1. Overview

The schema export tool export-schema.sh/bat is located in the tools directory. It can export schema from a specified database in IoTDB to a script file.

2. Detailed Functionality

2.1 Parameter

Short Param	Full Param	Description	Required	Default
`-h`	`-- host`	Hostname	No	127.0.0.1
`-p`	`--port`	Port number	No	6667
`-u`	`--username`	Username	No	root
`-pw`	`--password`	Password	No	`TimechoDB@2021`(Before V2.0.6 it is root)
`-sql_dialect`	`--sql_dialect`	Specifies whether the server uses`tree` model or`table` model	No	tree
`-db`	`--database`	Target database to export (only applies when`-sql_dialect=table`)	Required if`-sql_dialect=table`	-
`-table`	`--table`	Target table to export (only applies when`-sql_dialect=table`)	No	-
`-t`	`--target`	Output directory (created if it doesn't exist)	Yes
`-path`	`--path_pattern`	Path pattern for metadata export	Required if`-sql_dialect=tree`
`-pfn`	`--prefix_file_name`	Output filename prefix	No	`dump_dbname.sql`
`-lpf`	`--lines_per_file`	Maximum lines per dump file (only applies when`-sql_dialect=tree`)	No	`10000`
`-timeout`	`--query_timeout`	Query timeout in milliseconds (`-1`= no timeout)	No	-1Range：`-1 to Long. max=9223372036854775807`
`-help`	`--help`	Display help information	No

2.2 Command

Shell
# Unix/OS X
> tools/export-schema.sh [-sql_dialect<sql_dialect>] -db<database> -table<table>  
                [-h <host>] [-p <port>] [-u <username>] [-pw <password>] 
                -t <target_directory> [-path <exportPathPattern>] [-pfn <prefix_file_name>] 
                [-lpf <lines_per_file>] [-timeout <query_timeout>]
# Windows
# Before version V2.0.4.x
> tools\export-schema.bat [-sql_dialect<sql_dialect>] -db<database> -table<table>  
                [-h <host>] [-p <port>] [-u <username>] [-pw <password>] 
                -t <target_directory> [-path <exportPathPattern>] [-pfn <prefix_file_name>] 
                [-lpf <lines_per_file>] [-timeout <query_timeout>]
                
# V2.0.4.x and later versions
> tools\windows\schema\export-schema.bat [-sql_dialect<sql_dialect>] -db<database> -table<table>  
                [-h <host>] [-p <port>] [-u <username>] [-pw <password>] 
                -t <target_directory> [-path <exportPathPattern>] [-pfn <prefix_file_name>] 
                [-lpf <lines_per_file>] [-timeout <query_timeout>]

2.3 Examples

Export schema from database1 to /home:

./export-schema.sh -sql_dialect table -t /home/ -db database1

Output dump_database1.sql：

DROP TABLE IF EXISTS table1;
CREATE TABLE table1(
        time TIMESTAMP TIME,
        region STRING TAG,
        plant_id STRING TAG,
        device_id STRING TAG,
        model_id STRING ATTRIBUTE,
        maintenance STRING ATTRIBUTE,
        temperature FLOAT FIELD,
        humidity FLOAT FIELD,
        status BOOLEAN FIELD,
        arrival_time TIMESTAMP FIELD
);
DROP TABLE IF EXISTS table2;
CREATE TABLE table2(
        time TIMESTAMP TIME,
        region STRING TAG,
        plant_id STRING TAG,
        device_id STRING TAG,
        model_id STRING ATTRIBUTE,
        maintenance STRING ATTRIBUTE,
        temperature FLOAT FIELD,
        humidity FLOAT FIELD,
        status BOOLEAN FIELD,
        arrival_time TIMESTAMP FIELD
);