下面是我更喜欢使用的查询，做成一个视图:

CREATE VIEW vwForeignKeys AS
SELECT
   OBJECT_NAME(f.parent_object_id) TableName,
   COL_NAME(fc.parent_object_id,fc.parent_column_id) ColName,
   OBJECT_NAME (f.referenced_object_id) ReferencedTableName,
   COL_NAME(fc.referenced_object_id,fc.referenced_column_id) ReferencedColName,
   f.Name
FROM
   sys.foreign_keys AS f
INNER JOIN
   sys.foreign_key_columns AS fc
     ON f.OBJECT_ID = fc.constraint_object_id
INNER JOIN
   sys.tables t
      ON t.OBJECT_ID = fc.referenced_object_id

在您的例子中，查询看起来像这样

IF EXISTS(
   SELECT 1 
   FROM 
      vwForeignKeys 
   WHERE 
      TableName='table1' 
      AND ColName='column1' 
      AND ReferencedTableName='table2' 
      AND ReferencedColName='column2'
) THEN 
BEGIN
   --FOREIGN KEY EXISTS, DO SOMETHING
END