¿Por qué fallaría esta consulta? SELECT campaign, (seleccionar campaña) SUM(impressions) AS impressions FROM dsp_impressions

The query would fail because it attempts to use an aggregate function (SUM) on impressions alongside a non-aggregated column (campaign) without a GROUP BY clause. When you use an aggregate function, SQL requires you to specify how to group the non-aggregated columns. In this case, to get the sum of impressions per campaign, you would need GROUP BY campaign. The option "SELECT statements cannot be used to choose statistics from a table" is incorrect; SELECT is precisely how you retrieve data, including aggregated statistics. The option "There is no WHERE clause to filter the query results based on one or more conditions" is also incorrect; a WHERE clause is optional and not necessary for a query to be syntactically valid or to perform aggregation.