Add a row number to result set of a SQL query

Solution 1:

SELECT
    t.A,
    t.B,
    t.C,
    ROW_NUMBER() OVER (ORDER BY (SELECT 1)) AS number
FROM tableZ AS t

See working example at SQLFiddle

Of course, you may want to define the row-numbering order – if so, just swap OVER (ORDER BY (SELECT 1)) for, e.g., OVER (ORDER BY t.C), like in a normal ORDER BY clause.

Solution 2:

The typical pattern would be as follows, but you need to actually define how the ordering should be applied (since a table is, by definition, an unordered bag of rows). One way to do that if you don't care about a specific order otherwise is to use the leading key(s) of a covering index, the leading key(s) of the clustered index, or the columns in any group by / order by clauses. In this case I'll assume A is the single-column clustering key for t:

SELECT t.A, t.B, t.C, number = ROW_NUMBER() OVER (ORDER BY t.A)
  FROM dbo.tableZ AS t
  ORDER BY t.A;

If you truly don't care about order, you can generate arbitrary/nondeterministic row numbering using:

ROW_NUMBER() OVER (ORDER BY @@SPID)

-- or for serial plans

ROW_NUMBER() OVER (ORDER BY @@TRANCOUNT)

Little tricks I picked up from Paul White in this article (see "Paul's Solution").

Not sure what the variables in your question are supposed to represent (they don't match).

Add a row number to result set of a SQL query

Solution 1:

Solution 2:

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