Categories:: Metadata Functions

GET_DDL¶

Returns a DDL statement that can be used to recreate the specified object. For databases and schemas, GET_DDL is recursive (i.e. it returns the DDL statements for recreating all supported objects within the specified database/schema).

GET_DDL currently supports the following object types:

Databases (see CREATE DATABASE)
Schemas (see CREATE SCHEMA)
Tables (see CREATE TABLE)
External tables (see CREATE EXTERNAL TABLE)
Views (see CREATE VIEW)
Streams (see CREATE STREAM)
Tasks (see CREATE TASK)
Sequences (see CREATE SEQUENCE)
File formats (see CREATE FILE FORMAT)
Pipes (see CREATE PIPE)
UDFs, including external functions (see CREATE FUNCTION)
Stored procedures (see CREATE PROCEDURE)
Policies (see CREATE MASKING POLICY and CREATE ROW ACCESS POLICY)

Syntax¶

GET_DDL( '<object_type>' , '[<namespace>.]<object_name>' [ , <use_fully_qualified_names_for_recreated_objects> ] )

Arguments¶

Required:

object_type

Specifies the type of object for which the DDL is returned. Valid values (corresponding to the supported object types) are:

DATABASE
SCHEMA
TABLE (including for external tables)
VIEW (including for materialized views)
STREAM
TASK
SEQUENCE
FILE_FORMAT
PIPE
FUNCTION (for UDFs, including external functions)
PROCEDURE (for stored procedures)
POLICY (masking and row access policies)

namespace.object_name

Specifies the fully-qualified name of the object for which the DDL is returned.

Namespace is the database and/or schema in which the object resides:

Not used for databases.
For schemas, takes the form of database.
For schema objects (tables, views, streams, tasks, sequences, file formats, pipes, policies, and UDFs), takes the form of database.schema or schema.

Namespace is optional if a database and schema are currently in use within the user session; otherwise, it is required.

Optional:

use_fully_qualified_names_for_recreated_objects

If TRUE, the generated DDL statements use fully-qualified names for the objects to be recreated.

Default: FALSE.

Note

This does not affect the names of other objects referenced in the DDL statement (e.g. the name of a table referenced in a view definition).

Returns¶

Returns a string (VARCHAR) containing the text of the DDL statement that created the object.

For UDFs and stored procedures, the output might be slightly different from the original DDL. For example, if the UDF or stored procedure contains JavaScript code, the delimiter characters around the JavaScript code might be different. Also, if the original CREATE PROCEDURE statement did not specify EXECUTE AS OWNER or EXECUTE AS CALLER, the output from GET_DDL include EXECUTE AS OWNER because that is the default.

Usage Notes¶

The following notes apply to all supported objects:

object_type and object_name (including namespace if specified) must be enclosed in single quotes.
For object_type, TABLE and VIEW are interchangeable. If a TABLE object type is specified, and the object specified by name is a view, the function returns the DDL for the view and vice-versa.
If object_type is FUNCTION (i.e. UDF) and the UDF has arguments, you must include the argument data types as part of the function name, in the form of 'function_name( [ arg_data_type [ , ... ] ] )'.
If object_type is PROCEDURE and the stored procedure has arguments, then you must include the argument data types as part of the function name, in the form of 'procedure_name( [ arg_data_type [ , ... ] ] )'.
Querying this function for most Snowflake object types requires the same minimum permissions needed to view the object (using DESCRIBE <object> or SHOW <objects>). Snowflake restricts viewing special objects such as secure views to the owner (i.e. the role with the OWNERSHIP privilege on the object).

The following notes are specific to view objects:

The query result always:
- Returns lowercase SQL text for create or replace view, even if the casing in the original SQL statement used to create the view was uppercase or mixed case.
- Includes the OR REPLACE clause.
- Includes the SECURE property, if the view is secure.
- Excludes the COPY GRANTS view parameter, even if the original CREATE VIEW statement specifies the COPY GRANTS parameter.
- Generates the column list.
  
  If a masking policy is set on a column, the result specifies the masking policy for the column.
- Removes in-line SQL comments before the view body (i.e. AS). For example, in the following code, the comment immediately prior to the AS clause is removed:
```
create view view_t1
    -- GET_DDL() removes this comment.
    AS
    select * from t1;
```
If the view has a masking policy on one or more of its columns or a row access policy and the role executing the GET_DDL query does not have the global APPLY MASKING POLICY or the global APPLY ROW ACCESS POLICY privilege, as appropriate, Snowflake replaces the policy name with #unknown_policy.

If not removed prior to recreating the view, the #unknown_policy text causes the CREATE VIEW statement to fail. The intention of using this text is to indicate that the column or the view is protected by a policy.

If this text is present in the GET_DDL query result, prior to recreating the view, consult with your internal governance administrator to determine what policies are necessary for the columns or view, edit the GET_DDL query result, and then recreate the view.

Collation Details¶

Collation information is included in the input.

Examples¶

Return the DDL used to create a view named books_view:

select get_ddl('view', 'books_view');
+-----------------------------------------------------------------------------+ 
| GET_DDL('VIEW', 'BOOKS_VIEW')                                               |
|-----------------------------------------------------------------------------|
|                                                                             |
| create or replace view BOOKS_VIEW as select title, author from books_table; |
|                                                                             |
+-----------------------------------------------------------------------------+

Return the DDL used to create a schema named books_schema and the objects in the schema (the table books_table and the view books_view):

select get_ddl('schema', 'books_schema');
+-----------------------------------------------------------------------------+ 
| GET_DDL('SCHEMA', 'BOOKS_SCHEMA')                                           |
|-----------------------------------------------------------------------------|
| create or replace schema BOOKS_SCHEMA;                                      |
|                                                                             |
| create or replace TABLE BOOKS_TABLE (                                       |
| 	ID NUMBER(38,0),                                                      |
| 	TITLE VARCHAR(255),                                                   |
| 	AUTHOR VARCHAR(255)                                                   |
| );                                                                          |
|                                                                             |
| create or replace view BOOKS_VIEW as select title, author from books_table; |
|                                                                             |
+-----------------------------------------------------------------------------+

Return the DDL that uses fully-qualified names for the objects to be recreated:

select get_ddl('schema', 'books_schema', true);
+---------------------------------------------------------------------------------------------------+
| GET_DDL('SCHEMA', 'BOOKS_SCHEMA', TRUE)                                                           |
|---------------------------------------------------------------------------------------------------|
| create or replace schema BOOKS_DB.BOOKS_SCHEMA;                                                   |
|                                                                                                   |
| create or replace TABLE BOOKS_DB.BOOKS_SCHEMA.BOOKS_TABLE (                                       |
| 	ID NUMBER(38,0),                                                                            |
| 	TITLE VARCHAR(255),                                                                         |
| 	AUTHOR VARCHAR(255)                                                                         |
| );                                                                                                |
|                                                                                                   |
| create or replace view BOOKS_DB.BOOKS_SCHEMA.BOOKS_VIEW as select title, author from books_table; |
|                                                                                                   |
+---------------------------------------------------------------------------------------------------+

Note

As demonstrated in the example above, the DDL statement doesn’t use a fully-qualified name for the table used to create the view. To resolve the name of this table, Snowflake uses the name of the database and the name of the schema for the view.

Return the DDL used to create a UDF named multiply that has two parameters of type NUMBER:

select get_ddl('function', 'multiply(number, number)');

--------------------------------------------------+
 GET_DDL('FUNCTION', 'MULTIPLY(NUMBER, NUMBER)')  |
--------------------------------------------------+
 CREATE OR REPLACE "MULTIPLY"(A NUMBER, B NUMBER) |
 RETURNS NUMBER(38,0)                             |
 COMMENT='multiply two numbers'                   |
 AS 'a * b';                                      |
--------------------------------------------------+

Return the DDL to create a stored procedure named stproc_1 that has one parameter of type FLOAT:

SELECT GET_DDL('procedure', 'stproc_1(float)');
+---------------------------------------------------+
| GET_DDL('PROCEDURE', 'STPROC_1(FLOAT)')           |
|---------------------------------------------------|
| CREATE OR REPLACE PROCEDURE "STPROC_1"("F" FLOAT) |
| RETURNS FLOAT                                     |
| LANGUAGE JAVASCRIPT                               |
| EXECUTE AS OWNER                                  |
| AS '                                              |
| ''return F;''                                     |
| ';                                                |
+---------------------------------------------------+

Return the DDL to create a masking policy named employee_ssn_mask to mask social security numbers. Masked values are seen unless the user’s current role is PAYROLL.

select get_ddl('policy', 'employee_ssn_mask');

---------------------------------------------------------------------------+
                   GET_DDL('POLICY', 'EMPLOYEE_SSN_MASK')                  |
---------------------------------------------------------------------------+
create masking policy employee_ssn_mask as (val string) returns string ->  |
case                                                                       |
  when current_role() in ('PAYROLL')                                       |
  then val                                                                 |
  else '******'                                                            |
end;                                                                       |
---------------------------------------------------------------------------+