Returning Rows with a Specific Value First
In certain database queries, it can be desirable to prioritize the display of rows containing a specific value. For example, consider the following table:
Table: Users
id | name | city |
---|---|---|
1 | George | Seattle |
2 | Sam | Miami |
3 | John | New York |
4 | Amy | New York |
5 | Eric | Chicago |
6 | Nick | New York |
If we wish to retrieve the rows where the city column contains "New York" first, and then the remaining rows in alphabetical order of the city, we can utilize the following query:
SQL Server, Oracle, and DB2:
ORDER BY CASE WHEN city = 'New York' THEN 1 ELSE 2 END, city
This query employs a CASE expression to assign a priority of 1 to rows with "New York" as the city value and a priority of 2 otherwise. The ORDER BY clause then uses this priority along with the city column for sorting. Consequently, the rows with "New York" will be returned first, followed by the rest of the rows ordered alphabetically by city.
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