TSQL: Rowcounts of All Tables In A Server - tsql

Question

I am trying to obtain the row count of all tables in a server (NOT a particular database, but all the databases on a server, excluding the msdb, model, master, etc). I don't need any other details to be returned other than the database name, the table name, and row count.
My approach to this problem is to get all the databases in a server and place an id on them, which will be referred to in a while loop (beginning with id one until the maximum id). Then, within the while loop, I obtain the tables and row counts in the matching database ID. My problem is that the USE DatabaseName doesn't seem to allow me to make it dynamic, meaning that I can't store a database name in a variable and use it as the referred to database when performing the table with row count query.
Is there another approach to this that I'm missing (I've looked at many other examples - often using cursors, which seem to be much longer in code and appear to use more resources - this is a relatively fast query even if I use the largest database by tables, except that it doesn't hit the next database and so on), or am I missing something obvious in the code to make this dynamic?
DECLARE #ServerTable TABLE(
DatabaseID INT IDENTITY(1,1),
DatabaseName VARCHAR(50)
)
DECLARE #count INT
DECLARE #start INT = 1
SELECT #count = COUNT(*) FROM sys.databases WHERE name NOT IN ('master','tempdb','model','msdb')
INSERT INTO #ServerTable (DatabaseName)
SELECT name
FROM sys.databases
WHERE name NOT IN ('master','tempdb','model','msdb')
WHILE #start < #count
BEGIN
DECLARE #db VARCHAR(50)
SELECT #db = DatabaseName FROM #ServerTable WHERE DatabaseID = #start
-- This is the problem, as the USE doesn't seem to allow it to be dynamic.
USE #db
GO
SELECT #db
,o.name [Name]
,ddps.row_count [Row Count]
FROM sys.indexes AS i
INNER JOIN sys.objects AS o ON i.OBJECT_ID = o.OBJECT_ID
INNER JOIN sys.dm_db_partition_stats AS ddps ON i.OBJECT_ID = ddps.OBJECT_ID AND i.index_id = ddps.index_id
WHERE i.index_id < 2 AND o.is_ms_shipped = 0
ORDER BY o.NAME
SET #start = #start + 1
END
Note: I tried checking in the sys.objects and sys.indexes to see if I could filter with a database name, but I had no luck.
Update: I tried turning the SELECT into something dynamic with no success (note the below code only shows the change SELECT):
SET #sql = '
SELECT ' + #db + ' [Database]
,o.name [Name]
,ddps.row_count [Row Count]
FROM ' + #db + '.sys.objects
INNER JOIN ' + #db + ' sys.objects AS o ON i.OBJECT_ID = o.OBJECT_ID
INNER JOIN ' + #db + ' sys.dm_db_partition_stats AS ddps ON i.OBJECT_ID = ddps.OBJECT_ID AND i.index_id = ddps.index_id
WHERE i.index_id < 2 AND o.is_ms_shipped = 0
ORDER BY o.NAME'

Answer 1

No, that is essentially the way you do it.
I'm not sure why you think a while loop is faster than a cursor (though this is a common misconception). They are essentially the same thing. I don't always use cursors, but when I do, I use LOCAL FAST_FORWARD - make sure that you do too. See this article for more info:
What impact can different cursor options have?
To reduce the code required for individual tasks like this, you might be interested in the sp_MSforeachdb replacement I wrote (sp_MSforeachdb is a built-in, undocumented and unsupported stored procedure that will repeat a command for every database, but it is not possible to, say, filter out system databases, and it also has a severe bug where it will sometimes halt execution):
Making a more reliable and flexible sp_MSforeachdb
Execute a Command in the Context of Each Database in SQL Server
Another way would be dynamic SQL.
DECLARE #sql NVARCHAR(MAX) = N'';
SELECT #sql += '
SELECT db = N''' + name + '''
,o.name [Name]
,ddps.row_count [Row Count]
FROM ' + QUOTENAME(name) + '.sys.indexes AS i
INNER JOIN ' + QUOTENAME(name) + '.sys.objects AS o
ON i.OBJECT_ID = o.OBJECT_ID
INNER JOIN ' + QUOTENAME(name) + '.sys.dm_db_partition_stats AS ddps
ON i.OBJECT_ID = ddps.OBJECT_ID AND i.index_id = ddps.index_id
WHERE i.index_id < 2 AND o.is_ms_shipped = 0
ORDER BY o.NAME;'
FROM sys.databases
WHERE database_id > 4;
PRINT #sql;
--EXEC sp_executesql #sql;
(The print is there so that you can inspect the command before executing. It may be truncated at 8K if you have a large number of databases, but don't be alarmed - that is just a display issue in SSMS, the command is complete.)
You could also build a #temp table first, and insert into that, so that you have a single resultset to work with, e.g.
CREATE TABLE #x(db SYSNAME, o SYSNAME, rc SYSNAME);
DECLARE #sql NVARCHAR(MAX) = N'';
SELECT #sql += 'INSERT #x(db,o,rc)
SELECT db = N''' + name + '''
,o.name [Name]
,ddps.row_count [Row Count]
FROM ' + QUOTENAME(name) + '.sys.indexes AS i
INNER JOIN ' + QUOTENAME(name) + '.sys.objects AS o
ON i.OBJECT_ID = o.OBJECT_ID
INNER JOIN ' + QUOTENAME(name) + '.sys.dm_db_partition_stats AS ddps
ON i.OBJECT_ID = ddps.OBJECT_ID AND i.index_id = ddps.index_id
WHERE i.index_id < 2 AND o.is_ms_shipped = 0
ORDER BY o.NAME;'
FROM sys.databases
WHERE database_id > 4;
EXEC sp_executesql #sql;
SELECT db, o, rc FROM #x ORDER BY db, o;
Now, don't be fooled into believing this isn't also using a cursor or loop - it is. But it is building the command in a loop as opposed to executing it in a loop.

Answer 2

In terms of you making a dynamic query, rather than use a using, you could do a fully qualified name for your table names, using your selected #db variable.
So it would be 'FROM ' + #db+'.sys.objects' etc.
You would have to check that your DB name is valid (for instance, if you had a name that needed brackets for some reason).