php - Mysqli Getting Multiple Values from Multiple Tables -


i'm struggling figure out, , it's pretty simple can't work. using php/mysqli i'm trying data 2 tables, while first table have basis everything, second table may or may not have data matches first table's data, need second table return empty values. example...

first table 'cust':

customerid    name             school ------------------------------------------ 1623          bob smith        bon 1785          betty davis      foot 1854          john miller      beck 1547          kate lake        bon

second table 'ybk':

customerid      frame     type ------------------------------------------ 1623            001       cc 1854            012       cc

what these 2 tables bit variable between 2 things...

1) if want select school first table (for example cust.school='bon') result back:

customerid    name             school      frame     type --------------------------------------------------------- 1623          bob smith        bon         001       cc 1547          kate lake        bon

2) or, if select everything, result back:

customerid    name             school      frame     type --------------------------------------------------------- 1623          bob smith        bon         001       cc  1785          betty davis      foot 1854          john miller      beck        012       cc 1547          kate lake        bon

right now, when try different versions of select statement results in both tables instead of cust fields returning ybk ones if exist well. help! thank you!

this simple left join:

select * cust left join ybk using (custid) school='bon';  # custid, name,        school, frame, type '1547',   'kate lake', 'bon',  null,  null '1623',   'bob smith', 'bon',  '001', 'cc'

and 

select * cust left join ybk using (custid);  # custid, name,           school, frame,  type '1547',   'kate lake',    'bon',  null,   null '1623',   'bob smith',    'bon',  '001',  'cc' '1785',   'betty davis',  'foot', null,   null '1854',   'john miller',  'beck', '012',  'cc'

left join return rows first table in join, , fill null absent columns no matching row available in second table. rows matched on columns in using clause, helpfully coalesces matched columns in resulting output.

the full syntx given in mysql manual here


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