c# - storing and parsing boolean expressions in database -

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this follow-up question previous question which design pattern suitable workflow requirement?. know best way store boolean expression in database , evaluate @ runtime without effort. have requirement set of jobs need executed screen every month-end , decision of whether job can executed depends on outcome of previous jobs. should able save expression in database e = (a or b) , (c or d) (could complex nested expression). means e can run if or b successful , c or d successful. how can represented in database , parsed , condition evaluated later?

thinking of doing (not tested yet)
if "job e = (a , b) or (c , d)". store tree structure in table

 jobid dependentjobid successjobid failurejobid e                    b             c               e        c             d             0 e        d             1             0 e        b             1             0

this means "if successful, check b else check c", "if c successful check d". process starts highest node no "dependentjobid" , stops @ leaf node. use dummy job ids "1" success , "0" failure. if leaf node zero, job allowed run. not sure how best can evaluate in t-sql. may have use recursive function.

technology used: asp.net 3.5, c# 3.0, sql server 2008

you can store expressions strings in database , parse them @ runtime using either set of custom functions, or existing engine. achieve have used below in previous projects:

flee (fast lightweight expression evaluator)

dynamic linq

i dynamic linq easier go can construct clause using familiar linq / c# syntax , store string in database. have used flee in projects wanted construct own simple query language lot of these acheive using dynamic linq.


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