List tables on their dependency order based on foreign keys for Data Migration

If you want to perform bulk insert operation on multiple tables.

The tables have foreign key relationships between themselves.

If an INSERT operation is done on a table with a foreign key before the referenced table is being inserted to, the operation might fail due to violation of the foreign key.



Requirement



Produce a list of tables within a database ordered according to their dependencies.

Tables with no dependencies (no foreign keys) will be 1st.

Tables with dependencies only in the 1st set of tables will be 2nd.

Tables with dependencies only in the 1st or 2nd sets of tables will be 3rd.

and so on...





WITH cte (
 lvl
 ,object_id
 ,name
 ,schema_Name
 )
AS (
 SELECT 1
  ,object_id
  ,sys.tables.name
  ,sys.schemas.name AS schema_Name
 FROM sys.tables
 INNER JOIN sys.schemas ON sys.tables.schema_id = sys.schemas.schema_id
 WHERE type_desc = 'USER_TABLE'
  AND is_ms_shipped = 0
 
 UNION ALL
 
 SELECT cte.lvl + 1
  ,t.object_id
  ,t.name
  ,S.name AS schema_Name
 FROM cte
 JOIN sys.tables AS t ON EXISTS (
   SELECT NULL
   FROM sys.foreign_keys AS fk
   WHERE fk.parent_object_id = t.object_id
    AND fk.referenced_object_id = cte.object_id
   )
 JOIN sys.schemas AS S ON t.schema_id = S.schema_id
  AND t.object_id <> cte.object_id
  AND cte.lvl < 30
 WHERE t.type_desc = 'USER_TABLE'
  AND t.is_ms_shipped = 0
 )
SELECT schema_Name
 ,name
 ,MAX(lvl) AS dependency_level
FROM cte
WHERE schema_Name LIKE '%ORCA%'
GROUP BY schema_Name
 ,name
ORDER BY dependency_level
 ,schema_Name
 ,name;



Reference

Query to List all the partitioned tables in SQL Server database

select object_schema_name(i.object_id) as [schema],
    object_name(i.object_id) as [object],
    i.name as [index],
    s.name as [partition_scheme]
    from sys.indexes i
    join sys.partition_schemes s on i.data_space_id = s.data_space_id order by [schema]

Delete all Tables based on creation date

--Delete all Tables based on creation date



 DECLARE @tname VARCHAR(100)
DECLARE @sql VARCHAR(max)

DECLARE db_cursor CURSOR FOR
SELECT name AS tname
FROM sys.objects
WHERE create_date < GETDATE() - 1-- Days old

OPEN db_cursor
FETCH NEXT FROM db_cursor INTO @tname

WHILE @@FETCH_STATUS = 0
BEGIN
       SET @sql = 'DROP TABLE ' + @tname
       --EXEC (@sql)  -- For Executing
       PRINT @sql --For Printing

       FETCH NEXT FROM db_cursor INTO @tname
END

CLOSE db_cursor
DEALLOCATE db_cursor

Simplest way to Truncate/Delete all tables in a given database.

Simplest way to Truncate all tables in a given database.

Use databasename

EXEC sp_MSForEachTable 'Truncate TABLE ?' --- For Truncating all tables

Simplest way to Truncate all tables in a given database.

Use databasename

EXEC sp_MSforeachtable @command1 = "DROP TABLE ?"  --- For Deleting all tables

Script to generate drop all tables statements in a database in SQL Server

SELECT 'Drop table ' + NAME
FROM sys.objects
WHERE schema_name(schema_id) = 'dbo'
 AND type = 'u'

Script to find number of rows in each partition in a partitioned table in SQL Server

SELECT t.NAME [table]
 ,p.rows
 ,p.partition_number
 ,v.boundary_id
 ,v.value
FROM sys.tables t
INNER JOIN sys.partitions p ON p.object_id = t.object_id
INNER JOIN sys.partition_range_values v ON v.boundary_id = p.partition_number
WHERE is_ms_shipped = 0
ORDER BY [table]

Fastest way to row count all tables in a Database SQL Server

--Full Database
SELECT QUOTENAME(SCHEMA_NAME(sOBJ.schema_id)) + '.' + QUOTENAME(sOBJ.NAME) AS [TableName]
 ,SUM(sPTN.Rows) AS [RowCount]
FROM sys.objects AS sOBJ
INNER JOIN sys.partitions AS sPTN ON sOBJ.object_id = sPTN.object_id
WHERE sOBJ.type = 'U'
 AND sOBJ.is_ms_shipped = 0x0
 AND index_id < 2 -- 0:Heap, 1:Clustered
GROUP BY sOBJ.schema_id
 ,sOBJ.NAME
ORDER BY [TableName]
GO

-----------------------------------------------------------
-- For Individual Schema**
SELECT QUOTENAME(SCHEMA_NAME(sOBJ.schema_id)) + '.' + QUOTENAME(sOBJ.NAME) AS [TableName]
 ,SUM(sPTN.Rows) AS [RowCount]
FROM sys.objects AS sOBJ
INNER JOIN sys.partitions AS sPTN ON sOBJ.object_id = sPTN.object_id
WHERE sOBJ.type = 'U'
 AND sOBJ.is_ms_shipped = 0x0
 AND index_id < 2 -- 0:Heap, 1:Clustered
 AND QUOTENAME(SCHEMA_NAME(sOBJ.schema_id)) = '[YOURSCHEMANAMEHERE]'
GROUP BY sOBJ.schema_id
 ,sOBJ.NAME
ORDER BY [TableName]
GO