union

How to union two subqueries in SQLAlchemy and postgresql

由 旧街凉风 提交于 2019-12-22 04:47:13
问题 Raw SQL desired: SELECT id FROM (SELECT some_table.id FROM some_table WHERE some_table.some_field IS NULL) AS subq1 UNION (SELECT some_table.id WHERE some_table.some_field IS NOT NULL) LIMIT 10; Here is the python code: import sqlalchemy SOME_TABLE = sqlalchemy.Table( 'some_table', sqlalchemy.MetaData(), sqlalchemy.Column('id', sqlalchemy.Integer, primary_key=True), sqlalchemy.Column('some_field', sqlalchemy.Text)) stmt_1 = sqlalchemy.sql.select(SOME_TABLE.columns).where(SOME_TABLE.columns

Is this the correct way to use UNION ALL in a stored procedure?

由 回眸只為那壹抹淺笑 提交于 2019-12-21 17:19:00
问题 Is this the correct way to UNION ALL in a stored procedure? ALTER PROCEDURE [GetHomePageObjectPageWise] @PageIndex INT = 1 ,@PageSize INT = 10 ,@PageCount INT OUTPUT ,@whereStoryID varchar(2000) ,@whereAlbumID varchar(2000) ,@wherePictureID varchar(2000) AS BEGIN SET NOCOUNT ON; SELECT StoryID , AlbumID , StoryTitle , NULL AS AlbumName , (SELECT URL FROM AlbumPictures WHERE (AlbumID = dbo.Stories.AlbumID) AND (AlbumCover = 'True')) AS AlbumCover , Votes , NULL AS PictureId , 'stories' AS

SELECT data FROM two tables in MySQL

由 限于喜欢 提交于 2019-12-20 19:43:25
问题 What I have: The next structure: table_zero -> id (PRIMARY with auto increment) -> other table_1 -> id (foreign key to table zero id) -> varchar(80) Example value: (aahellobbb) -> one_field table_2 -> id (foreign key to table zero id) -> varchar(160) Example value: (aaececehellobbb) -> other_field What I want: Search and get an (id,varchar) array containing all matches with the LIKE '%str%' on the varchar field. For example, if I search with the "hello" string, then I should get both example

Python set Union and set Intersection operate differently?

由 我的未来我决定 提交于 2019-12-20 08:30:08
问题 I'm doing some set operations in Python, and I noticed something odd.. >> set([1,2,3]) | set([2,3,4]) set([1, 2, 3, 4]) >> set().union(*[[1,2,3], [2,3,4]]) set([1, 2, 3, 4]) That's good, expected behaviour - but with intersection: >> set([1,2,3]) & set([2,3,4]) set([2, 3]) >> set().intersection(*[[1,2,3], [2,3,4]]) set([]) Am I losing my mind here? Why isn't set.intersection() operating as I'd expect it to? How can I do the intersection of many sets as I did with union (assuming the [[1,2,3],

Python set Union and set Intersection operate differently?

由 ぃ、小莉子 提交于 2019-12-20 08:30:08
问题 I'm doing some set operations in Python, and I noticed something odd.. >> set([1,2,3]) | set([2,3,4]) set([1, 2, 3, 4]) >> set().union(*[[1,2,3], [2,3,4]]) set([1, 2, 3, 4]) That's good, expected behaviour - but with intersection: >> set([1,2,3]) & set([2,3,4]) set([2, 3]) >> set().intersection(*[[1,2,3], [2,3,4]]) set([]) Am I losing my mind here? Why isn't set.intersection() operating as I'd expect it to? How can I do the intersection of many sets as I did with union (assuming the [[1,2,3],

Mysql Union time V.S. separate query one by one [closed]

由 泄露秘密 提交于 2019-12-20 07:27:42
问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 7 years ago . If I have n queries q1, q2, q3 ... qn and each of them running t1, t2, t3 ... tn as the running time. Also I have another query q1 UNION ALL q2 UNION ALL q3 .... UNION ALL qn and running time is tu compare tu and

Performance/efficiency of 2 SELECT statements vs UNION vs anything else in MySQL-PHP

由 戏子无情 提交于 2019-12-20 04:24:10
问题 Which is more efficient/better practice/less costly in MySQL (with PHP)? SELECT ing two separate statements, UNION ing them into one, or something else I found online about CREATE ing a temporary table as the MySQL equivalent of SELECT INTO ? Or anything else you can think of? The result will be used in a PHP script. Queries: The first SELECT (let's call it Query A) will always yield 10 rows, 4 columns no matter what. The second SELECT (Query B) will always yield 1 row, 4 columns no matter

Insert into table variable with union

由 你离开我真会死。 提交于 2019-12-20 03:52:36
问题 I've got a table variable that I'm wanting to insert a union query. The union query runs fine, but I can't seem to get the insert to work (syntax error) INSERT INTO @table (a, b, c, d) VALUES (SELECT a, b, c, d FROM table1 UNION SELECT a, b, c, d FROM table2) Should this be working? I can post my real code if there is an issue elsewhere! I'm getting a syntax error on the first SELECT 回答1: INSERT INTO @table(a,b,c,d) SELECT a,b,c,d FROM table1 UNION SELECT a,b,c,d FROM table2 You do not need

mysql中union,union all 与order by 的常见用法

由 落爺英雄遲暮 提交于 2019-12-20 02:09:03
注意点： 多个复合查询使用一个orderby时，注意用AS后的属性名才行！ 例如： SELECT user_name AS userName , sco_re AS score FROM t1 WHERE user_name LIKE '王%' UNION SELECT user_name AS userName , sco_re AS score FROM t1 WHERE user_name LIKE '%m%' ORDER BY score ASC 具体使用见：https://www.cnblogs.com/pcheng/p/5939646.html 来源： CSDN 作者： 竹靠椅 链接： https://blog.csdn.net/weixin_45612794/article/details/103610187

联合体union

由 南笙酒味 提交于 2019-12-19 08:51:20
文章目录 1 union 1.1 union简介 1.2 利用union进行系统大小端的判断 1 union 1.1 union简介 C语言中的union在语法上与struct相似，union只分配最大成员的空间，所有成员共享这个空间。 1.2 利用union进行系统大小端的判断 我们需要知道union的使用受系统大小端的影响： 上图中的c永远是在低地址，所以我们可以利用这个特性进行系统大小端的判断，代码如下： # include <stdio.h> int system_mode ( ) { union SM { int i ; char c ; } ; union SM sm ; sm . i = 1 ; return sm . c ; } int main ( ) { printf ( "System Mode: %d\n" , system_mode ( ) ) ; return 0 ; } 参考资料： C语言进阶剖析教程 来源： CSDN 作者： SlowIsFastLemon 链接： https://blog.csdn.net/SlowIsFastLemon/article/details/103595279
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