sql - "x FOR y" in column definition of DB2 create table statement -


this db2 create table statement:

create table schema_f.table_a (     leafdescription f7uy2 char(10) ccsid 1141  not null default     ...

what leafdescription f7uy2 mean exactly?

tl;dr

it allows specify short name usable (older) rpg programs on , system utilities. in case, leafdescription long name usable sql, , f7uy2 usable inside rpg, etc (and sql, long names preferred obvious reasons).

it's part of system-specific behavior available on i.

see, (iseries, systemi, as/400) started out very different machine. several decades ago, before sql thing. , @ time, field , table names limited around 6 characters, , programs written in mind.

now, flash forward when sql comes around. on i, db2 sql got retrofitted (of sort) on top of existing file system. meant that, among other things, query on existing files sql without recreating or repopulating them.
unfortunately, meant stuck original, semi-cryptic names, in part because still had original programs too. if created (or re-created, case may be) table via sql, rpg programs couldn't reference it. allowed specify name could reference - meant switch sql-based tables (which had additional, new, advantages) without needing change programs. name-length restriction being lifted in recent versions of rpg, ability avoid renaming @ once boon.


Comments

Post a Comment

Popular posts from this blog

javascript - jQuery: Add class depending on URL in the best way -

i have html progress meter: <div class="col-md-3" style="margin-left: -20px;"> <div class="progress-pos active" id="progess-1"> <div class="progress-pos-inner"> login </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-2"> <div class="progress-pos-inner"> scan items </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-3"> <div class="progress-pos-inner"> confirm address </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-4"> <div class="progress-pos-in
Read more

caching - How to check if a url path exists in the service worker cache -

i need check if particular url path exists in service worker cache. example, suppose url is: /myserviceworker/service?a=110&b=70 this url exists in cache, there many of them different values of , b. now, suppose want refresh of these urls, how can that? i want know how access key values service worker cache. if know key, plan follows: var url = new url(key); if(url.pathname === "\/myserviceworker/service") refetch key but not sure how cache key , in format is. mean, string or url? cache api has match() method returns promise resolving in response object if match or undefined if no match exists. second parameter object can specify ignoresearch not take account url parameters. the ignoresearch option supported firefox ( chrome status here ). in other hand, retrieve cache entries, can use keys() method.
Read more

Redirect to a HTTPS version using .htaccess -

i need modify .htaccess file redirect urls https version without "www". http://example.com --> https://example.com http://www.example.com --> https://example.com https://www.example.com --> https://example.com this how .htaccess file looks like: rewriteengine on rewritecond %{request_filename} !-d rewritecond %{request_filename} !-f rewriterule ^(.*)$ redirect.php?id=$1&page=$2 [qsa,l] what modifications need make .htaccess in order forward https without "www"? it depends on doing current code. looks file called redirect trying display php page seo friendly url. think might confusing people. anyway, need , force https without www, need 1 more rule above. also second rule needs two capture groups in rewriterule test string because wanting 2 different values using $1 , $2 references. rewriteengine on #rediect www non www and/or http https --- combinations. rewritecond %{http_host} !^example\.com [nc,or] rewritecond %{https} !^
Read more