IS_DATABASE_ROLE_IN_SESSION¶

Syntax¶

Literal — specify a database role directly:

IS_DATABASE_ROLE_IN_SESSION( '<string_literal>' )

Nonliteral — specify a column:

IS_DATABASE_ROLE_IN_SESSION( <column_name> )

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Arguments¶

'string_literal'

The name of the database role.

Specify the relative name of the database role. The function evaluates to False if you specify the fully qualified name.

column_name

The column name in a table or view.

Returns¶

True

• For a literal argument (database role name), the current user’s active primary role or secondary roles in the session inherits the privileges of the specified database role.

• For a nonliteral argument (column name), Snowflake evaluates each row in the table and returns a row that contains a value that specifies a database role in the user’s current session. Each row corresponds to a database role name that originates from the database in use or the specified database in a query.

False

• For a literal argument, the specified database role is not in the role hierarchy of the current user’s primary role or secondary roles.

• For a nonliteral argument, Snowflake does not return a row if the database role is not in the table column for the database in use or the database specified in a query.

• Specifying the fully qualified name of a database role in the format database_name.database_role_name. Use the relative name instead, database_role_name.

Usage notes¶

These notes only apply to the IS_DATABASE_ROLE_IN_SESSION function:

• Use this table to predict the evaluation of the function when the function argument is a string literal:

  Context	Evaluation
  Query.	Session database.
  Table or view definition with WHERE clause.	Depends on the following: If you have a database in use and you use the relative name of the table or view, the context is the database in use (session database). If you specify the fully-qualified name of the table or view, the context is the database that contains the table or view.
  Protected table or view.	Database containing the table or view.
  Owner’s Rights stored procedure.	Database containing the stored procedure.
  Caller’s Rights stored procedure.	Session database.
  UDF	Database containing the protected table or view. If the UDF is not called in a policy, the function evaluates to the database that contains the UDF.

• A database role becomes active in the role hierarchy when the database containing the database role is in use or when querying a table in the same database that contains the database role.

• When you specify this function in the body of a data access policy, such as a masking or row access policy, the function uses the database and schema of the protected table.

  For example, if you add a row access policy to the hr.tables.empl_info table, the function searches for its argument, the database role name or the column name, in the hr database because that database contains the protected table.

• You should avoid query structures that require Snowflake to create an inline view. In this context, an inline view is a temporary view that Snowflake creates to determine the query result. For example, if your query calls this function and you specify a WITH clause at the beginning of the query or specify a subquery in the FROM clause, Snowflake returns an error:

  Could not resolve the database for IS_DATABASE_ROLE_IN_SESSION({})
  

  Where {} is a placeholder for the function argument in your query. The reason for the error is that Snowflake does not have enough information to evaluate the context of the function argument. To resolve the error message, simplify your query, such as removing the WITH clause or removing the subquery in the FROM clause.

• When the user property DEFAULT_SECONDARY_ROLES value is ALL, the function returns True if any account role granted to the user inherits the privileges of the specified database role.

• When using this function in the condition of a masking policy or row access policy that protects shared data, ensure the database containing the policy and the policy-protected data are both shared to the consumer account. The policy and the policy-protected data can be in the same database or in different databases. For details, see Share data protected by a policy.

These notes apply to both the IS_DATABASE_ROLE_IN_SESSION and IS_ROLE_IN_SESSION functions:

• Use one syntax.

• Name syntax:

  • Only one role name can be passed as an argument.

  • The argument must be a string and use the same casing as how the role is stored in Snowflake. For details, see Identifier requirements.

• Column syntax:

  • Only one column can be passed as an argument.

  • The column must have a STRING data type.

  • Specify the column as one of the following:

    • column_name

    • table_name.column_name

    • schema_name.table_name.column_name

    • database_name.schema_name.table_name.column_name

• Virtual columns:

  A virtual column, which contains the result of a calculated value from an expression rather than the calculated value being stored in the table, is not supported.

  SELECT IS_ROLE_IN_SESSION(UPPER(authz_role)) FROM t1;
  

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  A virtual column is supported only when the expression has an alias for the column name:

  CREATE VIEW v2 AS
  SELECT
    authz_role,
    UPPER(authz_role) AS upper_authz_role
  FROM t2;
  
  SELECT IS_ROLE_IN_SESSION(upper_authz_role) FROM v2;
  

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• Policies:

  If you use these functions with a masking policy or row access policy, verify that your Snowflake account is Enterprise Edition or higher.

  Snowflake recommends using this function when the policy conditions need to evaluate role hierarchy and inherited privileges.

• Result cache:

  If you use this function in a masking policy or row access policy and neither the policy nor the table or column protected by the policy change from a previous query, you can use the RESULT_SCAN function to return the results of a query on the protected table. The result cache applies when using the nonliteral syntax only.

• These functions cannot be used in the materialized view definition because the functions are not deterministic and Snowflake cannot determine what data to materialize.

Examples¶

Verify if the privileges granted to a specified role are inherited by the current role in the session:

SELECT IS_DATABASE_ROLE_IN_SESSION('R1');

+-----------------------------------+
| IS_DATABASE_ROLE_IN_SESSION('R1') |
+-----------------------------------+
| True                              |
+-----------------------------------+

Return database role values for the column named ROLE_NAME:

SELECT *
FROM myb.s1.t1
WHERE IS_DATABASE_ROLE_IN_SESSION(role_name);

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For additional examples related to secure data sharing, see Share data protected by a policy.