How do I specify unique constraint for multiple columns in MySQL? -

-

i have table:

table votes (     id,     user,     email,     address,     primary key(id), );

now want make columns user, email, address unique (together).

how do in mysql?

  • of course example just... example. please don't worry semantics.

alter table `votes` add unique `unique_index`(`user`, `email`, `address`);

Comments

Post a Comment

Popular posts from this blog

Listboxes in c# -

-
i have form 2 listboxes, listbox1 & listbox2. on form load filling both list boxes same no. of items. want if select item @ index 1 in listbox1 in listbox2 item same index should selected. how achieve this? subscribe on both listboxes selectionchanged event , set selectedindex accordingly opposite listbox.
Read more

Excel Duty List -

-
Image
i trying create duty roster class. background: have weekday , weekend duties. people duties on weekdays 1 point, while on weekends 2. problem: i'm wondering how code table in excel such whenever duty on weekday, recognizes person gets 1 point. my roster such: (where a,b,c row references) a name|points|date duty done on|date duty done on|date duty done on| b name|points|date duty done on|date duty done on|date duty done on| c name|points|date duty done on|date duty done on|date duty done on| i've tried following code, checks if date weekday, , count cell if is: {=sum(--(if(a:a<>", weekday(a:a)={2,3,4,5,6}))} for weekends, create separate column counts weekends, double points. in column called points , sum of weekday , weekend points. unfortunately above formula doesn't work keep getting #na , #value errors , in end i'm unable roster done. assuming have data shown in image below, where column a has names points s...
Read more

Multilayer CSV to filtered excel -

-
[enter image description here][1]i have following format csv hierarchy data (up 12 layers) , trying fill in excel can @ end create pivot of data. each file (over 1000) different, have been trying code macros unable remove bugs. first aproach create table , use above cell on blanks, because of layers not correct end of table any idea on how approach using macros? level 1,level 2,level 3,level 4,level 5,level 6,level 7,level 8,level 9,level 10,level 11,level 12 test ,,,,,components ,,,,,,default logic ,,,,,,,z04 - z05 ,,,,,,,,z04 () ,,,,,,,,,%pwr_pg_u_backlight% () components ,c ,,c802 - c842 ,,,c802 ,,,,1 (1) ,,,,2 (2) [this got| http://i.stack.imgur.com/bj2qg.png] [this need pivot| http://i.stack.imgur.com/7q6jq.png] to 'text columns' in vba row_count = 13 = 1 row_count strarray = split(cells(i, 1).value, ",") count = lbound(strarray) ubound(strarray) cells(i, count + 1).value = strarray(count) next next
Read more