sys.sql_expression_dependencies (Transact-SQL)

Artikkeli
05/23/2023

Applies to: SQL Server Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric

Contains one row for each by-name dependency on a user-defined entity in the current database. This includes dependences between natively compiled, scalar user-defined functions and other SQL Server modules. A dependency between two entities is created when one entity, called the referenced entity, appears by name in a persisted SQL expression of another entity, called the referencing entity. For example, when a table is referenced in the definition of a view, the view, as the referencing entity, depends on the table, the referenced entity. If the table is dropped, the view is unusable.

For more information, see Scalar User-Defined Functions for In-Memory OLTP.

You can use this catalog view to report dependency information for the following entities:

Schema-bound entities.
Non-schema-bound entities.
Cross-database and cross-server entities. Entity names are reported; however, entity IDs are not resolved.
Column-level dependencies on schema-bound entities. Column-level dependencies for non-schema-bound objects can be returned by using sys.dm_sql_referenced_entities.
Server-level DDL triggers when in the context of the master database.

Column name	Data type	Description
referencing_id	int	ID of the referencing entity. Is not nullable.
referencing_minor_id	int	Column ID when the referencing entity is a column; otherwise 0. Is not nullable.
referencing_class	tinyint	Class of the referencing entity. 1 = Object or column 12 = Database DDL trigger 13 = Server DDL trigger Is not nullable.
referencing_class_desc	nvarchar(60)	Description of the class of referencing entity. OBJECT_OR_COLUMN DATABASE_DDL_TRIGGER SERVER_DDL_TRIGGER Is not nullable.
is_schema_bound_reference	bit	1 = Referenced entity is schema-bound. 0 = Referenced entity is non-schema-bound. Is not nullable.
referenced_class	tinyint	Class of the referenced entity. 1 = Object or column 6 = Type 10 = XML schema collection 21 = Partition function Is not nullable.
referenced_class_desc	nvarchar(60)	Description of class of referenced entity. OBJECT_OR_COLUMN TYPE XML_SCHEMA_COLLECTION PARTITION_FUNCTION Is not nullable.
referenced_server_name	sysname	Name of the server of the referenced entity. This column is populated for cross-server dependencies that are made by specifying a valid four-part name. For information about multipart names, see Transact-SQL syntax conventions. NULL for non-schema-bound entities for which the entity was referenced without specifying a four-part name. NULL for schema-bound entities because they must be in the same database and therefore can only be defined using a two-part (schema.object) name.
referenced_database_name	sysname	Name of the database of the referenced entity. This column is populated for cross-database or cross-server references that are made by specifying a valid three-part or four-part name. NULL for non-schema-bound references when specified using a one-part or two-part name. NULL for schema-bound entities because they must be in the same database and therefore can only be defined using a two-part (schema.object) name.
referenced_schema_name	sysname	Schema in which the referenced entity belongs. NULL for non-schema-bound references in which the entity was referenced without specifying the schema name. Never NULL for schema-bound references because schema-bound entities must be defined and referenced by using a two-part name.
referenced_entity_name	sysname	Name of the referenced entity. Is not nullable.
referenced_id	int	ID of the referenced entity. The value of this column is never NULL for schema-bound references. The value of this column is always NULL for cross-server and cross-database references. NULL for references within the database if the ID cannot be determined. For non-schema-bound references, the ID cannot be resolved in the following cases: The referenced entity does not exist in the database. The schema of the referenced entity depends on the schema of the caller and is resolved at run time. In this case, is_caller_dependent is set to 1.
referenced_minor_id	int	ID of the referenced column when the referencing entity is a column; otherwise 0. Is not nullable. A referenced entity is a column when a column is identified by name in the referencing entity, or when the parent entity is used in a SELECT * statement.
is_caller_dependent	bit	Indicates that schema binding for the referenced entity occurs at runtime; therefore, resolution of the entity ID depends on the schema of the caller. This occurs when the referenced entity is a stored procedure, extended stored procedure, or a non-schema-bound user-defined function called in an EXECUTE statement. 1 = The referenced entity is caller dependent and is resolved at runtime. In this case, referenced_id is NULL. 0 = The referenced entity ID is not caller dependent. Always 0 for schema-bound references and for cross-database and cross-server references that explicitly specify a schema name. For example, a reference to an entity in the format `EXEC MyDatabase.MySchema.MyProc` is not caller dependent. However, a reference in the format `EXEC MyDatabase..MyProc` is caller dependent.
is_ambiguous	bit	Indicates the reference is ambiguous and can resolve at run time to a user-defined function, a user-defined type (UDT), or an xquery reference to a column of type xml. For example, assume that the statement `SELECT Sales.GetOrder() FROM Sales.MySales` is defined in a stored procedure. Until the stored procedure is executed, it is not known whether `Sales.GetOrder()` is a user-defined function in the `Sales` schema or column named `Sales` of type UDT with a method named `GetOrder()`. 1 = Reference is ambiguous. 0 = Reference is unambiguous or the entity can be successfully bound when the view is called. Always 0 for schema bound references.

Remarks

The following table lists the types of entities for which dependency information is created and maintained. Dependency information is not created or maintained for rules, defaults, temporary tables, temporary stored procedures, or system objects.

Note

Azure Synapse Analytics and Parallel Data Warehouse support tables, views, filtered statistics, and Transact-SQL stored procedures entity types from this list. Dependency information is created and maintained for tables, views, and filtered statistics only.

Entity type	Referencing entity	Referenced entity
Table	Yes*	Yes
View	Yes	Yes
Filtered index	Yes**	No
Filtered statistics	Yes**	No
Transact-SQL stored procedure***	Yes	Yes
CLR stored procedure	No	Yes
Transact-SQL user-defined function	Yes	Yes
CLR user-defined function	No	Yes
CLR trigger (DML and DDL)	No	No
Transact-SQL DML trigger	Yes	No
Transact-SQL database-level DDL trigger	Yes	No
Transact-SQL server-level DDL trigger	Yes	No
Extended stored procedures	No	Yes
Queue	No	Yes
Synonym	No	Yes
Type (alias and CLR user-defined type)	No	Yes
XML schema collection	No	Yes
Partition function	No	Yes

* A table is tracked as a referencing entity only when it references a Transact-SQL module, user-defined type, or XML schema collection in the definition of a computed column, CHECK constraint, or DEFAULT constraint.

** Each column used in the filter predicate is tracked as a referencing entity.

*** Numbered stored procedures with an integer value greater than 1 are not tracked as either a referencing or referenced entity.

Permissions

Requires VIEW DEFINITION permission on the database and SELECT permission on sys.sql_expression_dependencies for the database. By default, SELECT permission is granted only to members of the db_owner fixed database role. When SELECT and VIEW DEFINITION permissions are granted to another user, the grantee can view all dependencies in the database.

Examples

A. Returning entities that are referenced by another entity

The following example returns the tables and columns referenced in the view Production.vProductAndDescription. The view depends on the entities (tables and columns) returned in the referenced_entity_name and referenced_column_name columns.

USE AdventureWorks2022;  
GO  
SELECT OBJECT_NAME(referencing_id) AS referencing_entity_name,   
    o.type_desc AS referencing_description,   
    COALESCE(COL_NAME(referencing_id, referencing_minor_id), '(n/a)') AS referencing_minor_id,   
    referencing_class_desc,  
    referenced_server_name, referenced_database_name, referenced_schema_name,  
    referenced_entity_name,   
    COALESCE(COL_NAME(referenced_id, referenced_minor_id), '(n/a)') AS referenced_column_name,  
    is_caller_dependent, is_ambiguous  
FROM sys.sql_expression_dependencies AS sed  
INNER JOIN sys.objects AS o ON sed.referencing_id = o.object_id  
WHERE referencing_id = OBJECT_ID(N'Production.vProductAndDescription');  
GO

B. Returning entities that reference another entity

The following example returns the entities that reference the table Production.Product. The entities returned in the referencing_entity_name column depend on the Product table.

USE AdventureWorks2022;  
GO  
SELECT OBJECT_SCHEMA_NAME ( referencing_id ) AS referencing_schema_name,  
    OBJECT_NAME(referencing_id) AS referencing_entity_name,   
    o.type_desc AS referencing_description,   
    COALESCE(COL_NAME(referencing_id, referencing_minor_id), '(n/a)') AS referencing_minor_id,   
    referencing_class_desc, referenced_class_desc,  
    referenced_server_name, referenced_database_name, referenced_schema_name,  
    referenced_entity_name,   
    COALESCE(COL_NAME(referenced_id, referenced_minor_id), '(n/a)') AS referenced_column_name,  
    is_caller_dependent, is_ambiguous  
FROM sys.sql_expression_dependencies AS sed  
INNER JOIN sys.objects AS o ON sed.referencing_id = o.object_id  
WHERE referenced_id = OBJECT_ID(N'Production.Product');  
GO

C. Returning cross-database dependencies

The following example returns all cross-database dependencies. The example first creates the database db1 and two stored procedures that reference tables in the databases db2 and db3. The sys.sql_expression_dependencies table is then queried to report the cross-database dependencies between the procedures and the tables. Notice that NULL is returned in the referenced_schema_name column for the referenced entity t3 because a schema name was not specified for that entity in the definition of the procedure.

CREATE DATABASE db1;  
GO  
USE db1;  
GO  
CREATE PROCEDURE p1 AS SELECT * FROM db2.s1.t1;  
GO  
CREATE PROCEDURE p2 AS  
    UPDATE db3..t3  
    SET c1 = c1 + 1;  
GO  
SELECT OBJECT_NAME (referencing_id),referenced_database_name,   
    referenced_schema_name, referenced_entity_name  
FROM sys.sql_expression_dependencies  
WHERE referenced_database_name IS NOT NULL;  
GO  
USE master;  
GO  
DROP DATABASE db1;  
GO

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