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diff --git a/doc/sql_conventions.bb b/doc/sql_conventions.bb deleted file mode 100644 index f6a4e251f..000000000 --- a/doc/sql_conventions.bb +++ /dev/null @@ -1,91 +0,0 @@ -[h1]SQL Conventions[/h1] -[b]Intro[/b] -The following common SQL conventions appear throughout the code in many places. We use a simple DBA (DataBase Abstraction layer) to handle differences between databases. Please be sure to use only standards-compliant SQL. - -[b]Rule One[/b] -Worth Repeating: Don't use non-standard SQL. This goes for addons as well. If you do use non-standard SQL, and the dba funcs are insufficient, do a if()/switch() or similar for all currently supported databases. Currently nothing red# does requires non-standard SQL. - -[b]Using a format string[/b] -[li]Uses sprintf() -To be written -[code]// Example -$r = q("SELECT * FROM profile WHERE uid = %d", - local_channel() -); -[/code][/li] - -[b]Checking bit flags in a where clause[/b] -[li]You must explicitly convert integers to booleans. The easiest way to do this is to compare to 0. -[code]// Example -$r = q("SELECT abook_id, abook_flags, abook_my_perms, abook_their_perms, xchan_hash, xchan_photo_m, xchan_name, xchan_url from abook left join xchan on abook_xchan = xchan_hash where abook_channel = %d and not (abook_flags & %d)>0 ", - intval($uid), - intval(ABOOK_FLAG_SELF) -); -[/code] -[/li] -[li]Turning off a flag -[code]$y = q("update xchan set xchan_flags = (xchan_flags & ~%d) where (xchan_flags & %d)>0 and xchan_hash = '%s'", - intval(XCHAN_FLAGS_ORPHAN), - intval(XCHAN_FLAGS_ORPHAN), - dbesc($rr['hubloc_hash']) -);[/code] -[/li] -[li]Turning on a flag -[code]$y = q("update xchan set xchan_flags = (xchan_flags | %d) where xchan_hash = '%s'", - intval(XCHAN_FLAGS_ORPHAN), - dbesc($rr['hubloc_hash']) -);[/code] -[/li] - -[b]Using relative times (INTERVALs)[/b] -[li]Sometimes you want to compare something, like less than x days old. -[code]// Example -$r = q("SELECT * FROM abook left join xchan on abook_xchan = xchan_hash - WHERE abook_dob > %s + interval %s and abook_dob < %s + interval %s", - db_utcnow(), db_quoteinterval('7 day'), - db_utcnow(), db_quoteinterval('14 day') -);[/code] -[/li] -[b]Paged results[/b] -[li]To be written -[code]// Example -$r = q("SELECT * FROM mail WHERE uid=%d AND $sql_extra ORDER BY created DESC LIMIT %d OFFSET %d", - intval(api_user()), - intval($count), intval($start) -);[/code][/li] - -[b]NULL dates[/b] -[li]To be written -[code]// Example -$r = q("DELETE FROM mail WHERE expires != '%s' AND expires < %s ", - dbesc(NULL_DATE), - db_utcnow() -);[/code][/li] - -[b]Storing binary data[/b] -[li]To be written -[code]// Example -$x = q("update photo set data = '%s', height = %d, width = %d where resource_id = '%s' and uid = %d and scale = 0", - dbescbin($ph->imageString()), - intval($height), - intval($width), - dbesc($resource_id), - intval($page_owner_uid) -);[/code][/li] - -[b]Current timestamp[/b] -[li][code]// Example -$randfunc = db_getfunc('rand'); -$r = q("select xchan_url from xchan left join hubloc on hubloc_hash = xchan_hash where hubloc_connected > %s - interval %s order by $randfunc limit 1", - db_utcnow(), db_quoteinterval('30 day') -);[/code][/li] - -[b]SQL Function and Operator Abstraction[/b] -[li]Sometimes the same function or operator has a different name/symbol in each database. You use db_getfunc('funcname') to look them up. The string is [i]not[/i] case-sensitive; do [i]not[/i] include parens. -[code]// Example -$randfunc = db_getfunc('rand'); -$r = q("select xchan_url from xchan left join hubloc on hubloc_hash = xchan_hash where hubloc_connected > %s - interval %s order by $randfunc limit 1", - db_utcnow(), db_quoteinterval('30 day') -);[/code][/li] - -#include doc/macros/main_footer.bb;
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