common-table-expression

问题 When I run this CTE in SQL Server it says the syntax is incorrect by the declare statement. ;WITH cte as ( SELECT tblKBFolders.FolderID from tblKBFolders where FolderID = @FolderID UNION ALL SELECT tblKBFolders.FolderID FROM tblKBFolders INNER JOIN cte ON cte.FolderID = tblKBFolders.ParentFolderID ) declare @tblQueryFolders as table (FolderID uniqueidentifier) insert into @tblQueryFolders SELECT FolderID From cte; But if I move the declare to before the CTE, it runs just fine. declare

问题 Hell, I can't find a way to use the postgres 'WITH' clause with JOOQ. Could you please let me know if it's supported by JOOQ? Thanks 回答1: Common table expressions (the " WITH clause") are currently not supported in jOOQ. There is a pending feature request on the jOOQ road map for CTE's: #454. As of jOOQ 3.0, there are currently no plans of actually supporting it, though. (Your best option to push things a little bit is to discuss this topic on the jOOQ user group) 来源： https://stackoverflow

问题 Hell, I can't find a way to use the postgres 'WITH' clause with JOOQ. Could you please let me know if it's supported by JOOQ? Thanks 回答1: Common table expressions (the " WITH clause") are currently not supported in jOOQ. There is a pending feature request on the jOOQ road map for CTE's: #454. As of jOOQ 3.0, there are currently no plans of actually supporting it, though. (Your best option to push things a little bit is to discuss this topic on the jOOQ user group) 来源： https://stackoverflow

问题 Hell, I can't find a way to use the postgres 'WITH' clause with JOOQ. Could you please let me know if it's supported by JOOQ? Thanks 回答1: Common table expressions (the " WITH clause") are currently not supported in jOOQ. There is a pending feature request on the jOOQ road map for CTE's: #454. As of jOOQ 3.0, there are currently no plans of actually supporting it, though. (Your best option to push things a little bit is to discuss this topic on the jOOQ user group) 来源： https://stackoverflow

问题 It's hard for me to use words to describe this, so here's the sample: select * into t from (values (10, 'A'), (25, 'B'), (30, 'C'), (45, 'D'), (52, 'E'), (61, 'F'), (61, 'G'), (61, 'H'), (79, 'I'), (82, 'J') ) v(userid, name) Notice how F,G and H have the same userid. Now, consider the following recursive query: with tn as ( select t.userId,t.name, row_number() over (order by userid,newid()) as seqnum from t ), cte as ( select userId, name, seqnum as seqnum from tn where seqnum = 1 union all

问题 I am trying to pass some ids into an in-clause on a sorted index with the same order by condition but the query planner is explicitly sorting the data after performing index search. below are my queries. Generate a temporary table. SELECT a.n/20 as n, md5(a.n::TEXT) as b INTO temp_table From generate_series(1, 100000) as a(n); create an index CREATE INDEX idx_temp_table ON temp_table(n ASC, b ASC); In below query, planner uses index ordering and doesn't explicitly sorts the data.(expected)

问题 I'm using Maria DB version 10.2.9 on windows 7, MariaDB > select @@version; +----------------+ | @@version | +----------------+ | 10.2.9-MariaDB | +----------------+ I'm trying to use recursive CTE with INSERT SELECT to create some test Data. For simplicity follows below a single column table to be populated: CREATE TABLE cte_populated ( id INT NOT NULL PRIMARY KEY ) ENGINE = InnoDB; And the CTE which generates values 1 to 10: WITH RECURSIVE int_seq AS ( SELECT 1 AS val UNION ALL SELECT val +

问题 I am connecting Tableau with SQL Server and I am trying to use the T-SQL query. I just want to know, does Tableau support CTE (Common Table Expression)? I came across this article and it said CTE is possible: http://kb.tableau.com/articles/howto/using-common-table-expressions Here's my query: WITH Test (Store) AS ( SELECT Store FROM FiscalReporting.dbo.LBR_STR_ORG ) SELECT Store FROM Test When I am running this query, I get an error message. Please let me know if I am doing something wrong.

问题 I am connecting Tableau with SQL Server and I am trying to use the T-SQL query. I just want to know, does Tableau support CTE (Common Table Expression)? I came across this article and it said CTE is possible: http://kb.tableau.com/articles/howto/using-common-table-expressions Here's my query: WITH Test (Store) AS ( SELECT Store FROM FiscalReporting.dbo.LBR_STR_ORG ) SELECT Store FROM Test When I am running this query, I get an error message. Please let me know if I am doing something wrong.

问题 CTE (Common Table Expression) vs Temp tables or Table variables , which is faster? 回答1: We got a 50% increase in speed moving to CTE in one particular case so it's worth giving it a go but any performance related enhancements need to be bench marked so you can compare one against another. PS: we wrote more than one query with a CTE in it before we got the one we now use. 回答2: As I already said in my comment: IT DEPENDS! It really does depend on your query, your data (how much is there? What