除了大括号内的另一个大括号外,在大括号内用逗号分隔

split by comma inside braces except another braces inside braces

除了大括号内的另一个大括号外,我想在大括号内用逗号分隔

$q1 ="CREATE TABLE notes(id INTEGER,code DECIMAL (4,2),PRIMARY KEY (id))";
$q2 ="CREATE TABLE notes(id INTEGER,code TEXT)";

$r = preg_split('/\([^()]*\)(*SKIP)(*F)|[()]|,/', $q1);//$q1 splitted but $q2 no
print_r($r);

最终结果应该是:

$q1 :

   array(
         0 => id INTEGER
         1 => code DECIMAL (4,2)
         2 => PRIMARY KEY (id)
   );

$q2 :

   array(
        0 => id INTEGER
        1 => code TEXT
   );

如果嵌入的括号仅包含数字,则这样做:

$sqls = array(
"CREATE TABLE notes(id INTEGER,code DECIMAL (4,2),PRIMARY KEY (id))",
"CREATE TABLE notes(id INTEGER,code TEXT)"
);

foreach ($sqls as $sql) {
    $arr = preg_split("/(?<!\d)[(),](?!\d)/", $sql);
    print_r($arr);
}

输出:

Array
(
    [0] => CREATE TABLE notes
    [1] => id INTEGER
    [2] => code DECIMAL (4,2)
    [3] => PRIMARY KEY 
    [4] => id
    [5] => 
    [6] => 
)
Array
(
    [0] => CREATE TABLE notes
    [1] => id INTEGER
    [2] => code TEXT
    [3] => 
)

代码:(PHP Demo)

$sqls = array(
    "CREATE TABLE notes(id INTEGER,code DECIMAL (4,2),PRIMARY KEY (id))",
    "CREATE TABLE notes(id INTEGER,code TEXT)"
);

foreach($sqls as $sql){
    if(preg_match_all("/(?:^.+?\(|,)(?:\K[\w ]+(?:\([\S].*?\))?)/", $sql,$matches)){
        echo "<pre>";
            var_export($matches[0]);
        echo "</pre>";
    }
}

输出:

// first $matches...
array(
    0 => 'id INTEGER',
    1 => 'code DECIMAL (4,2)',
    2 => 'PRIMARY KEY (id)'
)
// second $matches...
array(
    0 => 'id INTEGER',
    1 => 'code TEXT'
)

正则表达式分解:(Regex Demo)

(?:^.+?\(|,)          #group everything from the start to 1st parenthesis or a comma
(?:\K[\w ]+           #\K means "only retain text from this point", group words and spaces
    (?:\([\S].*?\))?  #optionally group parenthetical text
)

使用 \K 允许排除捕获组和 preg_match_all returns 第一个子数组中的所需字符串(完整字符串)。好处是 $matches 数组的大小是带有捕获组的数组的一半。