yesod - Haskell/Persistent: Reusing "selectList" -

-

i trying write api in servant , writing lot of handlers this:

gettablea :: handler [arecord] gettablea =     xs <- rundb (selectlist [] [])     let records = map (\(entity _ v) -> v) xs     return records  gettableb :: handler [brecord] gettableb =     xs <- rundb (selectlist [] [])     let records = map (\(entity _ v) -> v) xs     return records  gettablec :: handler [crecord] gettablec =     xs <- rundb (selectlist [] [])     let records = map (\(entity _ v) -> v) xs     return records

and on.

i want able have more like

gettable :: handler [a] gettable =     xs <- rundb (selectlist [] [])     let records = map (\(entity _ v) -> v) xs     return records

however error

couldn't match expected type ‘sqlbackend’             actual type ‘persistentitybackend val’ relevant bindings include   getall :: handler [val] (bound @ src/novation/handler.hs:101:1) in first argument of ‘rundb’, namely ‘(selectlist [] [])’ in stmt of 'do' block: xs <- rundb (selectlist [] []) in expression:   { xs <- rundb (selectlist [] []);        let records = map (\ (entity _ v) -> ...) xs;        return records }

i hoping in end i'll able have this

server :: server myapi server = gettable :<|> gettable :<|> gettable  type myapi =           "tablea" :> '[json] [arecord]     :<|> "tableb" :> '[json] [brecord]     :<|> "tablec" :> '[json] [crecord]

instead of

server :: server myapi server = gettablea :<|> gettableb :<|> gettablec


Comments

Post a Comment

Popular posts from this blog

java - nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet Hibernate+SpringMVC -

-
i trying fetch records database , having above error this classs appropriate getters , setters public class user { private int id; private string username; private string password; private string email; i have create database , inserted data below configuration <bean id="datasource" class="org.apache.commons.dbcp2.basicdatasource" destroy-method="close"> <property name="driverclassname" value="com.mysql.jdbc.driver"/> <property name="url" value="jdbc:mysql://localhost:3306/usersdb"/> <property name="username" value="root"/> <property name="password" value=""/> </bean> this complete stacktrace severe: servlet.service() servlet [appservlet] in context path [/spring] threw exception [request processing failed; nested exception org.hibernate.exception.sqlgrammarexception: not ...
Read more

sql - Postgresql tables exists, but getting "relation does not exist" when querying -

-
Image
i have postgresql db number of tables. if query: select column_name information_schema.columns table_name="my_table"; i list of columns returned properly. however, when query: select * "my_table"; i error: (programmingerror) relation "my_table" not exist 'select *\n "my_table"\n' {} any thoughts on why can columns, can't query table? goal able query table. you have include schema if isnt public one select * <schema>."my_table" or can change default schema show search_path; set search_path my_schema; check table schema here select * information_schema.columns for example if table on default schema public both works ok select * parroquias_region select * public.parroquias_region but sectors need specify schema select * map_update.sectores_point
Read more

asp.net mvc - breakpoint on javascript in CSHTML? -

-
i have .cshtml file has javascript tag. within script tag have few lines of javascript. first line of javascript refers property in @viewbag. other javascript lines plain script without mvc related references. observation: can place breakpoints (visual studio 2015) on each of these javascript lines. however, breakpoints has white dot in center of breakpoint symbol (red circle) except line @viewbag reference (this particular line not have white dot in center). it seems breakpoint without white dot hit during run-time. question: can explain going on here? white dot mean? why plain red breakpoint line line hitting breakpoint? the visual studio debugger expecting debug actual server-side code within .cshtml file opposed client-side javascript within it. iirc, visual studio allow debug javascript code expected in internet explorer (and possibly edge), other browsers want use either third-party tool or developer tools (f12) within browser. an easy approach take advant...
Read more