sql - What is the difference between UNION and UNION ALL? - Stack …
Sep 8, 2008 · The UNION ALL command is equal to the UNION command, except that UNION ALL selects all values. The difference between Union and Union all is that Union all will not eliminate …
sql - Understanding union query - Stack Overflow
Mar 10, 2021 · UNION ALL - Includes duplicates. UNION - Excludes duplicates. A UNION operation is different from a JOIN: A UNION concatenates result sets from two queries. But a UNION does not …
sql - What is the difference between JOIN and UNION? - Stack Overflow
May 25, 2009 · 76 UNION combines the results of two or more queries into a single result set that includes all the rows that belong to all queries in the union. By using JOINs, you can retrieve data …
sql - How to UNION all two tables into a temp table? - Stack Overflow
Nov 30, 2022 · I've been trying to combine two tables into a temp table. My goal is to have the data of both tables available in one temp table I tried a couple of things: 1. SELECT * INTO #temp FROM …
Unioning two tables with different number of columns
Jan 11, 2018 · A union of two 1-row tables (two multiset relations each with one tuple) would have two rows (tuples) in the resulting relation. In relational algebra (which SQL isn't) the union result might be …
sql - "union" to avoid duplicates - Stack Overflow
Dec 3, 2024 · https://dbfiddle.uk/zspUa8WK I need to export name and sum the invoice of my customer since 2022. So I need to get only customers which bought since 2 years and the sum. No problem …
WHERE statement after a UNION in SQL? - Stack Overflow
Mar 27, 2011 · Basically, the UNION is looking for two complete SELECT statements to combine, and the WHERE clause is part of the SELECT statement. It may make more sense to apply the outer …
How to order by with union in SQL? - Stack Overflow
Per the SQL Standard, the order of results is undefined barring an explicit order by clause. That first select in your example probably returns its results in the order returned by the subselect, but it is not …
sql - UNION with WHERE clause - Stack Overflow
Mar 20, 2017 · I'm doing a UNION of two queries on an Oracle database. Both of them have a WHERE clause. Is there a difference in the performance if I do the WHERE after UNIONing the queries …
SQL Server: How to use UNION with two queries that BOTH have a …
SQL Server: How to use UNION with two queries that BOTH have a WHERE clause? Asked 14 years, 9 months ago Modified 4 years, 6 months ago Viewed 146k times