Mysql Query Search - mysql

Question

I need to search columns (shown below) in a table called t_npc , for a specific value i but have failed many times.
example (does not work)
SELECT * FROM t_npc WHERE a_item_0 LIKE '%a_item_%' = 123;
SELECT * FROM t_npc WHERE 'a_item_0' <=> 'a_item_19' = 123;
SELECT a_index FROM t_npc WHERE a_item_0 LIKE 'a_item_%' = 123;
SELECT a_index, a_name FROM t_npc WHERE t_npc.a_item_0 or t_npc.a_item_1 or t_npc.a_item_2 or t_npc.a_item_4 = 44;
and many others to search the column names below for a value but it never works. I have tried wild cards with these columns still with not luck.
`a_item_0` int(11) NOT NULL DEFAULT '-1',
`a_item_1` int(11) NOT NULL DEFAULT '-1',
`a_item_2` int(11) NOT NULL DEFAULT '-1',
`a_item_3` int(11) NOT NULL DEFAULT '-1',
`a_item_4` int(11) NOT NULL DEFAULT '-1',
`a_item_5` int(11) NOT NULL DEFAULT '-1',
`a_item_6` int(11) NOT NULL DEFAULT '-1',
`a_item_7` int(11) NOT NULL DEFAULT '-1',
`a_item_8` int(11) NOT NULL DEFAULT '-1',
`a_item_9` int(11) NOT NULL DEFAULT '-1',
`a_item_10` int(11) NOT NULL DEFAULT '-1',
`a_item_11` int(11) NOT NULL DEFAULT '-1',
`a_item_12` int(11) NOT NULL DEFAULT '-1',
`a_item_13` int(11) NOT NULL DEFAULT '-1',
`a_item_14` int(11) NOT NULL DEFAULT '-1',
`a_item_15` int(11) NOT NULL DEFAULT '-1',
`a_item_16` int(11) NOT NULL DEFAULT '-1',
`a_item_17` int(11) NOT NULL DEFAULT '-1',
`a_item_18` int(11) NOT NULL DEFAULT '-1',
`a_item_19` int(11) NOT NULL DEFAULT '-1',

Answer 1

select value from table where field = 'value'
or
select value from table where field like '%value%'
You are doing both, which will not work. Provide more detail on what you want to accomplish, but from what you asked, that is why your query is not working.
You can, however do:
select value from table where field_a = 'valuea' AND field_b like '%valueb'

Answer 2

You should be using a different table structure.
Try something like this
CREATE TABLE npc (
Npc_id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
PRIMARY KEY (Npc_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
CREATE TABLE item (
Npc_id bigint(20) unsigned NOT NULL,
Item_id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
Item_value int(11) NOT NULL,
PRIMARY KEY (Item_id),
KEY Npc_id (Npc_id),
CONSTRAINT Item_ibfk_1 FOREIGN KEY (Npc_id) REFERENCES Npc (Npc_id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

Answer 3

The long way:
SELECT a_index, a_name FROM t_npc WHERE
t_npc.a_item_0 = 44 or t_npc.a_item_1 = 44 or t_npc.a_item_2 = 44
...
or t_npc.a_item19 = 44;
Slightly better you can use IN :
select a_index, a_name from t_npc where 44 in
(a_item_0, a_item_1, a_item_2, a_item3,
...
a_item18, a_item19);
You should also create an t_npc_items table instead of having so many fields on t_npc.
[You could generate the sql by querying the field names from the information_schema and then executing that command, but metasql makes unicorns cry.]