Some ideas and implementations of wildcard * matching in MYSQL Query _ MySQL

How to implement the wildcard * matching function in MYSQL Query and bitsCN.com

When sending a short message on the site today, you may encounter a function that is to perform a wildcard search for an account.

The following situations may be used for search:

Sunzhongshan string searches without wildcards

Sun * starts with sun

* Shan ends with shan.

Sun * shan starts with sun and ends with shan

* Zhong * contains zhong

Sun * ong * starts with sun and contains ong

The first thought is to make a judgment. if it starts with "*", how should it be handled. Then process the strings one by one using the * array separator.

In this case, a large number of functions are used for judgment, which is a waste of resources. So I decided to rethink my ideas .....

.......................

The last code written by sun * is usename LIKE 'Sun %'

* Zhong * The last written code is usename LIKE '% zhong %'

......................................

In this way, I want to replace * with % before processing.

Taking sun * zhong * as an example, you can replace it with sun % zhong %, which seems to be implemented, but it is difficult to separate and convert

Finally, we can use %, % to replace it. after replacement, sun %, % zhong %, %

Then, the trim () function is used to process the preceding and following % symbols.

Then it is split into arrays by explode (). The preceding string is split into arrays (0 => sun %, 1 => % zhong %, 2 =>)

If there are spaces, you can skip the loop.

Example code completed:

$ SQL = "SELECT autoid FROM users WHERE 1 = 1 ";

$ Str1 = 'Sun * zhong *';

$ Str11 = str_replace ('*', '%, %', $ str1 );

$ Str12 = trim ($ str11, '% ');

$ Str13 = explode (",", $ str12 );

Foreach ($ str13 as $ strStr ){

If (emptyempty ($ strStr )){

Continue;

}

$ SQL. = "AND username LIKE '". $ strStr ."'";

}

Echo $ SQL;

// Execution result:

// SELECT autoid FROM users WHERE 1 = 1 AND username LIKE 'Sun % 'AND username LIKE' % zhong %'

?>

From: the growth path of golden pig's PHP

BitsCN.com