Know relationships between all the tables of database in SQL Server

Question

I wish to all know how the tables in my database are related to each other (i.e PK/FK/UK) and hence i created a database diagram of all my tables in SQL Server. The diagram

Answer 1

This stored procedure will provide you with a hierarchical tree of relationship. Based on this article from Technet. It will also optionally provide you a query for reading or deleting all the related data.

IF OBJECT_ID('GetForeignKeyRelations','P') IS NOT NULL 
    DROP PROC GetForeignKeyRelations 
GO 

CREATE PROC GetForeignKeyRelations 
@Schemaname Sysname = 'dbo' 
,@Tablename Sysname 
,@WhereClause NVARCHAR(2000) = '' 
,@GenerateDeleteScripts bit  = 0  
,@GenerateSelectScripts bit  = 0 

AS 

SET NOCOUNT ON 

DECLARE @fkeytbl TABLE 
( 
ReferencingObjectid        int NULL 
,ReferencingSchemaname  Sysname NULL 
,ReferencingTablename   Sysname NULL  
,ReferencingColumnname  Sysname NULL 
,PrimarykeyObjectid     int  NULL 
,PrimarykeySchemaname   Sysname NULL 
,PrimarykeyTablename    Sysname NULL 
,PrimarykeyColumnname   Sysname NULL 
,Hierarchy              varchar(max) NULL 
,level                  int NULL 
,rnk                    varchar(max) NULL 
,Processed                bit default 0  NULL 
); 



 WITH fkey (ReferencingObjectid,ReferencingSchemaname,ReferencingTablename,ReferencingColumnname 
            ,PrimarykeyObjectid,PrimarykeySchemaname,PrimarykeyTablename,PrimarykeyColumnname,Hierarchy,level,rnk) 
    AS 
    ( 
        SELECT                   
                               soc.object_id 
                              ,scc.name 
                              ,soc.name 
                              ,convert(sysname,null) 
                              ,convert(int,null) 
                              ,convert(sysname,null) 
                              ,convert(sysname,null) 
                              ,convert(sysname,null) 
                              ,CONVERT(VARCHAR(MAX), scc.name + '.' + soc.name  ) as Hierarchy 
                              ,0 as level 
                              ,rnk=convert(varchar(max),soc.object_id) 
        FROM SYS.objects soc 
        JOIN sys.schemas scc 
          ON soc.schema_id = scc.schema_id 
       WHERE scc.name =@Schemaname 
         AND soc.name =@Tablename 
      UNION ALL 
      SELECT                   sop.object_id 
                              ,scp.name 
                              ,sop.name 
                              ,socp.name 
                              ,soc.object_id 
                              ,scc.name 
                              ,soc.name 
                              ,socc.name 
                              ,CONVERT(VARCHAR(MAX), f.Hierarchy + ' --> ' + scp.name + '.' + sop.name ) as Hierarchy 
                              ,f.level+1 as level 
                              ,rnk=f.rnk + '-' + convert(varchar(max),sop.object_id) 
        FROM SYS.foreign_key_columns sfc 
        JOIN Sys.Objects sop 
          ON sfc.parent_object_id = sop.object_id 
        JOIN SYS.columns socp 
          ON socp.object_id = sop.object_id 
         AND socp.column_id = sfc.parent_column_id 
        JOIN sys.schemas scp 
          ON sop.schema_id = scp.schema_id 
        JOIN SYS.objects soc 
          ON sfc.referenced_object_id = soc.object_id 
        JOIN SYS.columns socc 
          ON socc.object_id = soc.object_id 
         AND socc.column_id = sfc.referenced_column_id 
        JOIN sys.schemas scc 
          ON soc.schema_id = scc.schema_id 
        JOIN fkey f 
          ON f.ReferencingObjectid = sfc.referenced_object_id 
        WHERE ISNULL(f.PrimarykeyObjectid,0) <> f.ReferencingObjectid 
      ) 

     INSERT INTO @fkeytbl 
     (ReferencingObjectid,ReferencingSchemaname,ReferencingTablename,ReferencingColumnname 
            ,PrimarykeyObjectid,PrimarykeySchemaname,PrimarykeyTablename,PrimarykeyColumnname,Hierarchy,level,rnk) 
     SELECT ReferencingObjectid,ReferencingSchemaname,ReferencingTablename,ReferencingColumnname 
            ,PrimarykeyObjectid,PrimarykeySchemaname,PrimarykeyTablename,PrimarykeyColumnname,Hierarchy,level,rnk 
       FROM fkey 

        SELECT F.Relationshiptree 
         FROM 
        ( 
        SELECT DISTINCT Replicate('------',Level) + CASE LEVEL WHEN 0 THEN '' ELSE '>' END +  ReferencingSchemaname + '.' + ReferencingTablename 'Relationshiptree' 
               ,RNK 
          FROM @fkeytbl 
          ) F 
        ORDER BY F.rnk ASC 

------------------------------------------------------------------------------------------------------------------------------- 
-- Generate the Delete / Select script 
------------------------------------------------------------------------------------------------------------------------------- 

    DECLARE @Sql VARCHAR(MAX) 
    DECLARE @RnkSql VARCHAR(MAX) 

    DECLARE @Jointables TABLE 
    ( 
    ID INT IDENTITY 
    ,Object_id int 
    ) 

    DECLARE @ProcessTablename SYSNAME 
    DECLARE @ProcessSchemaName SYSNAME 

    DECLARE @JoinConditionSQL VARCHAR(MAX) 
    DECLARE @Rnk VARCHAR(MAX) 
    DECLARE @OldTablename SYSNAME 

    IF @GenerateDeleteScripts = 1 or @GenerateSelectScripts = 1  
    BEGIN 

          WHILE EXISTS ( SELECT 1 
                           FROM @fkeytbl 
                          WHERE Processed = 0 
                            AND level > 0 ) 
          BEGIN 

            SELECT @ProcessTablename = '' 
            SELECT @Sql                 = '' 
            SELECT @JoinConditionSQL = '' 
            SELECT @OldTablename     = '' 


            SELECT TOP 1 @ProcessTablename = ReferencingTablename 
                  ,@ProcessSchemaName  = ReferencingSchemaname 
                  ,@Rnk = RNK  
              FROM @fkeytbl 
             WHERE Processed = 0 
              AND level > 0  
             ORDER BY level DESC 


            SELECT @RnkSql ='SELECT ' + REPLACE (@rnk,'-',' UNION ALL SELECT ')  

            DELETE FROM @Jointables 

            INSERT INTO @Jointables 
            EXEC(@RnkSql) 

            IF @GenerateDeleteScripts = 1 
                SELECT @Sql = 'DELETE [' + @ProcessSchemaName + '].[' + @ProcessTablename + ']' + CHAR(10) + ' FROM [' + @ProcessSchemaName + '].[' + @ProcessTablename + ']' + CHAR(10) 

            IF @GenerateSelectScripts = 1 
                SELECT @Sql = 'SELECT  [' + @ProcessSchemaName + '].[' + @ProcessTablename + '].*' + CHAR(10) + ' FROM [' + @ProcessSchemaName + '].[' + @ProcessTablename + ']' + CHAR(10) 

            SELECT @JoinConditionSQL = @JoinConditionSQL  
                                           + CASE  
                                             WHEN @OldTablename <> f.PrimarykeyTablename THEN  'JOIN ['  + f.PrimarykeySchemaname  + '].[' + f.PrimarykeyTablename + '] ' + CHAR(10) + ' ON ' 
                                             ELSE ' AND '  
                                             END 
                                           + ' ['  + f.PrimarykeySchemaname  + '].[' + f.PrimarykeyTablename + '].[' + f.PrimarykeyColumnname + '] =  ['  + f.ReferencingSchemaname  + '].[' + f.ReferencingTablename + '].[' + f.ReferencingColumnname + ']' + CHAR(10)  
                     , @OldTablename = CASE  
                                         WHEN @OldTablename <> f.PrimarykeyTablename THEN  f.PrimarykeyTablename 
                                         ELSE @OldTablename 
                                         END 

                  FROM @fkeytbl f 
                  JOIN @Jointables j 
                    ON f.Referencingobjectid  = j.Object_id 
                 WHERE charindex(f.rnk + '-',@Rnk + '-') <> 0 
                   AND F.level > 0 
                 ORDER BY J.ID DESC 

            SELECT @Sql = @Sql +  @JoinConditionSQL 

            IF LTRIM(RTRIM(@WhereClause)) <> ''  
                SELECT @Sql = @Sql + ' WHERE (' + @WhereClause + ')' 

            PRINT @SQL 
            PRINT CHAR(10) 

            UPDATE @fkeytbl 
               SET Processed = 1 
             WHERE ReferencingTablename = @ProcessTablename 
               AND rnk = @Rnk 

          END 

          IF @GenerateDeleteScripts = 1 
            SELECT @Sql = 'DELETE FROM [' + @Schemaname + '].[' + @Tablename + ']' 

          IF @GenerateSelectScripts = 1 
            SELECT @Sql = 'SELECT * FROM [' + @Schemaname + '].[' + @Tablename + ']' 

          IF LTRIM(RTRIM(@WhereClause)) <> ''  
                SELECT @Sql = @Sql  + ' WHERE ' + @WhereClause 

         PRINT @SQL 
     END 

SET NOCOUNT OFF 


go