大括号内用逗号分隔，大括号内的另一个大括号除外

Question

我想用大括号内的逗号分隔，除了大括号内的另一个大括号

$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
   );

Answer 1

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，preg_match_all 在第一个子数组中返回所需的字符串（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。

Answer 2

如果嵌入的括号仅包含数字，则可以这样做：

$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] => 
)