如何使用 PHP PDO 检查 MySQL 中是不是存在表？ [复制]

Posted 2023-05-08

【中文标题】如何使用 PHP PDO 检查 MySQL 中是不是存在表？ [复制]

【英文标题】：How to check if a table exists in MySQL using PHP PDO? [duplicate]如何使用 PHP PDO 检查 MySQL 中是否存在表？ [复制]

【发布时间】：2018-02-22 11:45:23

【问题描述】：

if($count <= 0 ) // IF TABLE DOES NOT EXIST -> CREATE AND INSERT DATA

    $CREATE_TABLE= "CREATE TABLE $TABLE_NAME LIKE student; INSERT $TABLE_NAME SELECT * FROM student;";
    $created = $connect->exec($CREATE_TABLE);

    if($created!=FALSE)
    
        $SQL = "INSERT INTO $TABLE_NAME (name, roll_number, father_name, dob, gender, address, email, phone, department, program, semester, section) VALUES(:name, :roll_number, :father_name, :dob, :gender, :address, :email, :phone, :department, :program, :semester, :section)";
        $pdo_statement = $connect->prepare($SQL);

        $pdo_statement->bindparam(':name',          $name);
        $pdo_statement->bindparam(':roll_number',   $roll_number);
        $pdo_statement->bindparam(':father_name',   $father_name);
        $pdo_statement->bindparam(':dob',           $dob);
        $pdo_statement->bindparam(':gender',        $gender);
        $pdo_statement->bindparam(':address',       $address);
        $pdo_statement->bindparam(':email',         $email);
        $pdo_statement->bindparam(':phone',         $phone);
        $pdo_statement->bindparam(':department',    $department);
        $pdo_statement->bindparam(':program',       $program);
        $pdo_statement->bindparam(':semester',      $semester);
        $pdo_statement->bindparam(':section',       $section);

        $result = $pdo_statement->execute();
    

else if($count > 0) // IF TABLE EXIST -> INSERT DATA

    $SQL = "INSERT INTO $TABLE_NAME (name, roll_number, father_name, dob, gender, address, email, phone, department, program, semester, section) VALUES (:name, :roll_number, :father_name, :dob, :gender, :address, :email, :phone, :department, :program, :semester, :section)";
    $pdo_statement = $connect->prepare($SQL);

    $pdo_statement->bindparam(':name',          $name);
    $pdo_statement->bindparam(':roll_number',   $roll_number);
    $pdo_statement->bindparam(':father_name',   $father_name);
    $pdo_statement->bindparam(':dob',           $dob);
    $pdo_statement->bindparam(':gender',        $gender);
    $pdo_statement->bindparam(':address',       $address);
    $pdo_statement->bindparam(':email',         $email);
    $pdo_statement->bindparam(':phone',         $phone);
    $pdo_statement->bindparam(':department',    $department);
    $pdo_statement->bindparam(':program',       $program);
    $pdo_statement->bindparam(':semester',      $semester);
    $pdo_statement->bindparam(':section',       $section);

    $result = $pdo_statement->execute();

 // ELSE IF ENDS

【问题讨论】：

检查：***.com/questions/37597538/…

最好是查询 information_schema.TABLES 表。 dev.mysql.com/doc/refman/5.7/en/tables-table.html

您应该在if 语句之前发布代码，因为您似乎正在检查该表是否存在...

为什么要检查表是否存在..？

@KunalAwasthi Haan Bhai

【参考方案1】：

所以我知道您将创建表，如果它不存在并插入数据。所以先打电话

$pdo->query("CREATE TABLE $TABLE IF NOT EXISTS;");

当表存在时，它什么也不做。

然后插入你的数据。

$pdo->query("INSERT INTO $TABLE ... ");

php 中没有“if then else”！

【参考方案2】：

function tableExists($pdo, $table)

// Try a select statement against the table
// Run it in try/catch in case PDO is in ERRMODE_EXCEPTION.
try 
    $result = $pdo->query("SELECT 1 FROM $table LIMIT 1");
 catch (Exception $e) 
    // We got an exception == table not found
    return FALSE;


// Result is either boolean FALSE (no table found) or PDOStatement Object (table found)
return $result !== FALSE;