The DISTINCT has no effect on the MIN() function like other aggregate functions such as SUM(), AVG()and COUNT(). The advantage is that you can select other columns in the result as well (besides the key and value) :. To get the minimum amount of … Unlike other aggregate functions e.g., SUM, COUNT, and AVG, the DISTINCT modifier is not applicable to the MIN() function. Top. Summary: in this tutorial, you will learn how to use the SQL DISTINCT operator to remove duplicates from a result set. When I see DISTINCT in the outer level, that usually indicated that the developer didn't properly analyze the cardinality of the child tables and how the joins worked, and they slapped a DISTINCT on the end result to eliminate duplicates that are the result of a poorly thought out join (or that could have been resolved through the judicious use of DISTINCT on an inner sub-query).
Unlike other aggregate functions e.g., SUM, COUNT, and AVG, the DISTINCT modifier is not applicable to the MIN() function. und die Werte werden jeweils nur einmal angezeigt.. Der Befehl Distinct kommt weniger in transaktionalen Datenbanken vor. Oracle SELECT DISTINCT examples. For other DBMSs, that have window functions (like Postgres, SQL-Server, Oracle, DB2), you can use them like this. SQL Server 2019 improves the performance of SQL COUNT DISTINCT operator using a new Approx_count_distinct function. SQL MIN function examples Similar to the MAX function, the MIN function ignores NULL values. How to use SQL DISTINCT. The DISTINCT modifier is only for ISO compatibility. SQL MIN function examples MySQL supports all the five (5) ISO standard aggregate functions COUNT, SUM, AVG, MIN and MAX. Let’s look at some examples of using SELECT DISTINCT to see how it works. It is a good practice to always use DISTINCT instead of UNIQUE. The DISTINCT clause can be used only in the SELECT statement. SUM and AVG functions only work on numeric data. If you want to exclude duplicate values from the aggregate function results, use the DISTINCT keyword. GILT FÜR: SQL Server Azure SQL-Datenbank Azure Synapse Analytics (SQL Data Warehouse) Parallel Data Warehouse APPLIES TO: SQL Server Azure SQL Database Azure Synapse Analytics (SQL Data Warehouse) Parallel Data Warehouse Eine Unterabfrage ist eine Abfrage, die in einer SELECT … A) Using MySQL MIN() function to find the minimum value in all rows. Ian on July 16, 2018 February 14, 2020. Unterabfragen (SQL Server) Subqueries (SQL Server) 02/18/2018; 18 Minuten Lesedauer; In diesem Artikel. Therefore, it returns the non-NULL minimum value in a set of values. SQL DISTICT clause. Typically, the expression would be a range of values returned as separate rows in a column, and you can use this function to find the minimum value from the returned rows. The expression can be a column or an expression that consists of columns and operators. The primary key ensures that the table has no duplicate rows. MIN() – Find the Minimum Value in a Column in MySQL.
SELECT key, value FROM tableX ( SELECT key, value, ROW_NUMBER() OVER (PARTITION BY key ORDER BY whatever) --- ORDER BY NULL AS rn --- for example FROM tableX ) tmp WHERE rn = 1 ;