CREATE RESOURCE LABEL

Description

CREATE RESOURCE LABEL is used to create a resource label.

Precautions

Only users with the POLADMIN or SYSADMIN permission, or the initial user can perform this operation.

Syntax

    
         CREATE RESOURCE LABEL [IF NOT EXISTS] label_name ADD label_item_list[, ...];

Click to enlarge

label_item_list
1

resource_type(resource_path[, ...])

resource_type

{ TABLE | COLUMN | SCHEMA | VIEW | FUNCTION }

Parameters

IF NOT EXISTS
If a resource label with the same name already exists, no error is generated. Instead, a message is displayed, indicating that the resource label already exists.

label_name
Specifies the resource label name, which must be unique.

Value range: a string. It must comply with Identifier Naming Conventions and contain a maximum of 63 characters. If the value contains more than 63 characters, the database truncates it and retains the first 63 characters as the resource label name. If a resource label name contains uppercase letters, the database automatically converts the uppercase letters into lowercase letters. To create a resource label name that contains uppercase letters, enclose the resource label name with double quotation marks ("").

The identifier must be lowercase letters, uppercase letters, underscores (_), digits (0–9), or dollar signs ($) and must start with a letter or underscore (_).
resource_type
Specifies the type of database resources to be labeled.

Value range: TABLE, COLUMN, SCHEMA, VIEW, and FUNCTION.
resource_path
Specifies the path of database resources.

Examples

    
         -- Create table tb_for_label.
gaussdb=# CREATE TABLE tb_for_label(col1 text, col2 text, col3 text);

-- Create a resource label based on a table.
gaussdb=# CREATE RESOURCE LABEL IF NOT EXISTS table_label add TABLE(public.tb_for_label);

-- Create an existing table resource label again and compare the differences between adding IF NOT EXISTS and not adding IF NOT EXISTS.
gaussdb=# CREATE RESOURCE LABEL IF NOT EXISTS table_label add TABLE(public.tb_for_label);
NOTICE:  table_label label already defined, skipping
CREATE RESOURCE LABEL
gaussdb=# CREATE RESOURCE LABEL table_label add TABLE(public.tb_for_label);
ERROR:  table_label label already defined

-- Create a resource label based on columns.
gaussdb=# CREATE RESOURCE LABEL IF NOT EXISTS column_label add COLUMN(public.tb_for_label.col1);

-- Create schema schema_for_label.
gaussdb=# CREATE SCHEMA schema_for_label;

-- Create a resource label based on a schema.
gaussdb=# CREATE RESOURCE LABEL IF NOT EXISTS schema_label add SCHEMA(schema_for_label);

-- Create view view_for_label.
gaussdb=# CREATE VIEW view_for_label AS SELECT 1;

-- Create a resource label based on a view.
gaussdb=# CREATE RESOURCE LABEL IF NOT EXISTS view_label add VIEW(view_for_label);

-- Create function func_for_label.
gaussdb=# CREATE FUNCTION func_for_label RETURNS TEXT AS $$ SELECT col1 FROM tb_for_label; $$ LANGUAGE SQL;

-- Create a resource label based on a function.
gaussdb=# CREATE RESOURCE LABEL IF NOT EXISTS func_label add FUNCTION(func_for_label);

-- Delete the table resource label table_label.
gaussdb=# DROP RESOURCE LABEL IF EXISTS table_label; 

-- Delete the column resource label column_label.
gaussdb=# DROP RESOURCE LABEL IF EXISTS column_label;

-- Delete the function resource label func_for_label.
gaussdb=# DROP FUNCTION func_for_label;

-- Delete the view resource label view_for_label.
gaussdb=# DROP VIEW view_for_label;

-- Delete the schema resource label schema_for_label.
gaussdb=# DROP SCHEMA schema_for_label;

-- Delete the tb_for_label table.
gaussdb=# DROP TABLE tb_for_label;