alias

问题 I understand that oracle does not allow AS commands for table aliases, so I've been suggested a solution like below. SELECT Temp.avgsale FROM (SELECT o.received, AVG(p.price*d.qty+d.sfee) avgsale FROM orders o, parts p, odetails d GROUP BY o.received) Temp WHERE Temp.avgsale=(SELECT MIN(Temp.avgsale) FROM Temp); However, I am getting the following error when I run it: ERROR at line 4: ORA-00942: table or view does not exist . I also get similar errors when I try to set the alias at the

问题 If we define and use an alias B within another alias A, the first time execution of A will fail. For example, alias A='alias B="which ls"; B;' The first time excution would look like (in bash) bash: B: command not found The example above is a simplified construction. in practice, we might meet such usage implicitly. The reason might be: when we execute the alias A, all expansions are carried out before execution, but B is undefined when we execute A for the first time. So is there a way to

问题 I have two primary MySQL tables (profiles and contacts) with many supplementary tables (prefixed by prm_). They are accessed and manipulated via PHP. In this instance I am querying the profiles table where I will retrieve an Owner ID and a Breeder ID. This will then be referenced against the contacts table where the information on the Owners and Breeders is kept. I received great help here on another question regarding joins and aliases, where I was also furnished with the following query.

问题 While working on my class declaration I'm having some confusion on how to use alias templates and template variables within in a non class template while trying to use auto type deduction. Signal.h #ifndef SIGNAL_H #define SIGNAL_H #include <cstdint> template<typename T> using TimeSignal = T; using DiscreteTime = TimeSignal<std::uint8_t>; using ContinuousTime = TimeSignal<double>; class Signal { private: template<typename T> static TimeSignal<T> time_; double voltage_; double current_; public

问题 SQL> -- CASE 1 SQL>select nest_test.id.num from nest_test; select nest_test.id.num from nest_test * ERROR at line 1: ORA-00904: "NEST_TEST"."ID"."NUM": invalid identifier SQL> -- CASE 2 SQL>select n.id.num from nest_test n; ID.NUM ---------- 12 As, AFAIK, aliasing any table is just giving simple name to the table or column. Then, why I'm getting error in Case 1 , when I'm trying to retrieve user defined object from table ? What actually happened, when I aliased my table. 回答1: The Oracle

问题 I'm wondering if there is a general SQL syntax allowing for selecting unaliased numeric literals from sub-selects: -- Seems to work in MySQL / Oracle select table_alias."1" from ( select 1 from dual ) table_alias I know I could alias the fields in the subselect: -- Works everywhere select table_alias.column_alias from ( select 1 column_alias from dual ) table_alias But what if I don't have control over the subselect? Also, some RDBMS allow to provide both table AND column aliases when

问题 I'm emulating PostgreSQL style generate_series() table-valued functions in SQL Server as such: CREATE FUNCTION generate_series(@d1 DATE, @d2 DATE) RETURNS TABLE AS RETURN -- Ignore implementation (returning a single DATE column) for this question This can now be used as expected: SELECT * FROM generate_series( CAST ('2005-07-01' AS DATE), CAST ('2005-07-31' AS DATE) ) t Now I'd like to use derived column list syntax to rename columns along with the table as such: SELECT * FROM generate_series

问题 I am working on multiple projects with similar structures and sub-directories. An example of the hierarchy would be something like this: Where X is the project name and subdirectories Main , Libs , Lx and Mx are all the same for different projects. insteding of cd'ing betweeing ong paths, I would like to create an alias (or a simple command) to jump to a directory (eg: Libs/ M2 ) regardless of the project name and the sub-directory that I am in (whether I am in L1 or L8 , or project_red or

问题 i'm writing the following SQL query for my Postgres database: SELECT( (SELECT count(*) as A FROM merchant WHERE nome LIKE 'A%'), (SELECT count(*) as B FROM merchant WHERE nome LIKE 'B%'), (SELECT count(*) as C FROM merchant WHERE nome LIKE 'C%'), (SELECT count(*) as D FROM merchant WHERE nome LIKE 'D%'), (SELECT count(*) as E FROM merchant WHERE nome LIKE 'E%'), (SELECT count(*) as F FROM merchant WHERE nome LIKE 'F%'), (SELECT count(*) as G FROM merchant WHERE nome LIKE 'G%'), (SELECT count(

问题 I have a site developed and is working fine on development machine (Mac OS X 10.7). However when I port it over to a Linux server I ran into error: Alias "application.extensions.langhandler.ElangHandler" is invalid. Make sure it points to an existing PHP file It supposedly is a permission problem according the below article: http://code.google.com/p/yii/issues/detail?id=3039 However, I checked and the protected/extensions folder and down all have 755 permission. I even tried t make them all