fk.sql

SELECT
    fk.name AS constraint_name,
    sch1.name AS [table_schema],
    tab1.name AS [table_name],
    sch2.name AS [ref_table_schema],
    tab2.name AS [ref_table],
    (
        SELECT
            col1.name AS [column],
            col2.name AS [referenced_column]
        FROM sys.foreign_key_columns fkc
        INNER JOIN sys.columns col1
            ON col1.column_id = fkc.parent_column_id AND col1.object_id = tab1.object_id
        INNER JOIN sys.columns col2
            ON col2.column_id = fkc.referenced_column_id AND col2.object_id = tab2.object_id 
        WHERE fk.object_id = fkc.constraint_object_id
        FOR JSON PATH
    ) AS column_mapping,
    fk.delete_referential_action_desc AS [on_delete],
    fk.update_referential_action_desc AS [on_update]
FROM sys.foreign_keys fk
INNER JOIN sys.objects obj
    ON obj.object_id = fk.referenced_object_id
INNER JOIN sys.tables tab1
    ON tab1.object_id = fk.parent_object_id
INNER JOIN sys.schemas sch1
    ON tab1.schema_id = sch1.schema_id
INNER JOIN sys.tables tab2
    ON tab2.object_id = fk.referenced_object_id
INNER JOIN sys.schemas sch2
    ON tab2.schema_id = sch2.schema_id for json path;