Try with: ( select * from _member_facebook inner join _member_pts ON _member_facebook._fb_owner=_member_pts._username where _member_facebook._promote_point = 9 ORDER BY RAND() limit 2 ) UNION ALL ( select * from _member_facebook inner join _member_pts ON _member_facebook._fb_owner=_member_pts._username where _member_facebook._promote_point = 8 limit 3 ) Although, I think you should put the ORDER BY clause at the end of … Read more
There are a number of ways to do this, depending on what you really want. With no common columns, you need to decide whether you want to introduce a common column or get the product. Let’s say you have the two tables: parts: custs: +—-+———-+ +—–+——+ | id | desc | | id | name … Read more
If you are trying to union multiple CTEs, then you need to declare the CTEs first and then use them: With Clients As ( Select Client_No From dbo.Decision_Data Group By Client_No Having Count(*) = 1 ) , CTE2 As ( Select Client_No From dbo.Decision_Data Group By Client_No Having Count(*) = 2 ) Select Count(*) From … Read more
In Scala you just have to append all missing columns as nulls. import org.apache.spark.sql.functions._ // let df1 and df2 the Dataframes to merge val df1 = sc.parallelize(List( (50, 2), (34, 4) )).toDF(“age”, “children”) val df2 = sc.parallelize(List( (26, true, 60000.00), (32, false, 35000.00) )).toDF(“age”, “education”, “income”) val cols1 = df1.columns.toSet val cols2 = df2.columns.toSet val … Read more
Either the article you read used a bad example, or you misinterpreted their point. select username from users where company = ‘bbc’ or company = ‘itv’; This is equivalent to: select username from users where company IN (‘bbc’, ‘itv’); MySQL can use an index on company for this query just fine. There’s no need to … Read more
Sometimes you need to have the ORDER BY in each of the sections that need to be combined with UNION. In this case SELECT * FROM ( SELECT table1.field1 FROM table1 ORDER BY table1.field1 ) DUMMY_ALIAS1 UNION ALL SELECT * FROM ( SELECT table2.field1 FROM table2 ORDER BY table2.field1 ) DUMMY_ALIAS2
If it is a list, you can also use AddRange method. var listB = new List<int>{3, 4, 5}; var listA = new List<int>{1, 2, 3, 4, 5}; listA.AddRange(listB); // listA now has elements of listB also. If you need new list (and exclude the duplicate), you can use Union var listB = new List<int>{3, 4, … Read more
This is a very good question. I implemented the same algorithm on c# some time ago. The Algorithm constructs a common contour of two polygons (i.e. Constructs a union without holes). Here it is. Step 1. Create graph that describes the polygons. Input: first polygon (n points), second polygon (m points). Output: graph. Vertex – … Read more
Quoting the docs, To apply ORDER BY or LIMIT to an individual SELECT, place the clause inside the parentheses that enclose the SELECT: (SELECT a FROM t1 WHERE a=10 AND B=1 ORDER BY a LIMIT 10) UNION (SELECT a FROM t2 WHERE a=11 AND B=2 ORDER BY a LIMIT 10);
Here’s a quick little module I wrote that allows you to UNION multiple scopes. It also returns the results as an instance of ActiveRecord::Relation. module ActiveRecord::UnionScope def self.included(base) base.send :extend, ClassMethods end module ClassMethods def union_scope(*scopes) id_column = “#{table_name}.id” sub_query = scopes.map { |s| s.select(id_column).to_sql }.join(” UNION “) where “#{id_column} IN (#{sub_query})” end end end … Read more