获取SQL语句中使用的所有表的名称

Question

I have dynamic SQL statement generated using criteria. This statement involves multiple joins using many tables. Requirement is to get list of all the tables used in this statement.

For example:

SELECT 
    table1.a, table2.b, ... 
FROM 
    table1 
INNER JOIN 
    table2 ON table1.col1 = table2.col1 
LEFT OUTER JOIN 
    table3 ON table2.col3 = table3.col1

I want to get list of tables used in the above query dynamically like:

table1,table2,table3.

I am using C# and SQL Server. I think parsing the string and finding individual tables will be complex. Is there any way we can get the list of Tables used in a query from SQL Server itself?

Answer 1

If you have sufficient permission (eg CREATE/DROP VIEW , VIEW DEFINITION ) here's a possible solution that lets SQL Server do most of the work, meaning you won't have to parse the SQL:

1. Extend your dynamic SQL so that it creates a (temporary) view with your SELECT query behind it:

    CREATE VIEW schema.someRandomUniqueName WITH SCHEMABINDING AS SELECT schema.table1.a, schema.table2.b, ... FROM schema.table1 INNER JOIN schema.table2 ON a.col1=b.col1 LEFT OUTER JOIN schema.table3 ON schema.table2.col3 = schema.table3.col1; 

   Some points to observe:

   • Make sure to specify WITH SCHEMABINDING .
   • Make sure that each table or view name is fully qualified, ie includes the schema name. This requirements comes from the schema binding option.
   • You could create a unique temporary view name eg via String.Format("_{0:N}", Guid.NewGuid()) .
     

2. Query sys.dm_sql_referenced_entities for the created view. This will give you the database objects that your SELECT query depends on. (The following example is untested:)

    SELECT referenced_schema_name, referenced_entity_name, referenced_class_desc FROM sys.dm_sql_referenced_entities ('schema.someRandomUniqueName', 'OBJECT'); 

3. DROP the temporary view; it's no longer needed.