快捷導(dǎo)航

mysql存儲(chǔ)過(guò)程之返回多個(gè)值的方法示例

更新時(shí)間：2019年12月23日 11:36:55 作者：luyaran

這篇文章主要介紹了mysql存儲(chǔ)過(guò)程之返回多個(gè)值的方法,結(jié)合實(shí)例形式分析了mysql存儲(chǔ)過(guò)程返回多個(gè)值的實(shí)現(xiàn)方法與PHP調(diào)用技巧,需要的朋友可以參考下

本文實(shí)例講述了mysql存儲(chǔ)過(guò)程之返回多個(gè)值的方法。分享給大家供大家參考，具體如下：

mysql存儲(chǔ)函數(shù)只返回一個(gè)值。要開(kāi)發(fā)返回多個(gè)值的存儲(chǔ)過(guò)程，需要使用帶有INOUT或OUT參數(shù)的存儲(chǔ)過(guò)程。咱們先來(lái)看一個(gè)orders表它的結(jié)構(gòu)：

mysql> desc orders;
+----------------+-------------+------+-----+---------+-------+
| Field     | Type    | Null | Key | Default | Extra |
+----------------+-------------+------+-----+---------+-------+
| orderNumber  | int(11)   | NO  | PRI | NULL  |    |
| orderDate   | date    | NO  |   | NULL  |    |
| requiredDate  | date    | NO  |   | NULL  |    |
| shippedDate  | date    | YES |   | NULL  |    |
| status     | varchar(15) | NO  |   | NULL  |    |
| comments    | text    | YES |   | NULL  |    |
| customerNumber | int(11)   | NO  | MUL | NULL  |    |
+----------------+-------------+------+-----+---------+-------+
7 rows in set

然后嘞，咱們來(lái)看一個(gè)存儲(chǔ)過(guò)程，它接受客戶編號(hào)，并返回發(fā)貨(shipped)，取消(canceled)，解決(resolved)和爭(zhēng)議(disputed)的訂單總數(shù)：

DELIMITER $$
CREATE PROCEDURE get_order_by_cust(
 IN cust_no INT,
 OUT shipped INT,
 OUT canceled INT,
 OUT resolved INT,
 OUT disputed INT)
BEGIN
 -- shipped
 SELECT
      count(*) INTO shipped
    FROM
      orders
    WHERE
      customerNumber = cust_no
        AND status = 'Shipped';
 -- canceled
 SELECT
      count(*) INTO canceled
    FROM
      orders
    WHERE
      customerNumber = cust_no
        AND status = 'Canceled';
 -- resolved
 SELECT
      count(*) INTO resolved
    FROM
      orders
    WHERE
      customerNumber = cust_no
        AND status = 'Resolved';
 -- disputed
 SELECT
      count(*) INTO disputed
    FROM
      orders
    WHERE
      customerNumber = cust_no
        AND status = 'Disputed';
END

其實(shí)，除IN參數(shù)之外，存儲(chǔ)過(guò)程還需要4個(gè)額外的OUT參數(shù)：shipped, canceled, resolved 和 disputed。在存儲(chǔ)過(guò)程中，使用帶有count函數(shù)的select語(yǔ)句根據(jù)訂單狀態(tài)獲取相應(yīng)的訂單總數(shù)，并將其分配給相應(yīng)的參數(shù)。按著上面的sql，我們?nèi)绻褂胓et_order_by_cust存儲(chǔ)過(guò)程，可以傳遞客戶編號(hào)和四個(gè)用戶定義的變量來(lái)獲取輸出值。執(zhí)行存儲(chǔ)過(guò)程后，我們?cè)偈褂肧ELECT語(yǔ)句輸出變量值：

+----------+-----------+-----------+-----------+
| @shipped | @canceled | @resolved | @disputed |
+----------+-----------+-----------+-----------+
|    22 |     0 |     1 |     1 |
+----------+-----------+-----------+-----------+
1 row in set

結(jié)合實(shí)際應(yīng)用，我們?cè)賮?lái)看下從PHP程序中調(diào)用返回多個(gè)值的存儲(chǔ)過(guò)程：

<?php
/**
 * Call stored procedure that return multiple values
 * @param $customerNumber
 */
function call_sp($customerNumber)
{
  try {
    $pdo = new PDO("mysql:host=localhost;dbname=yiibaidb", 'root', '123456');
    // execute the stored procedure
    $sql = 'CALL get_order_by_cust(:no,@shipped,@canceled,@resolved,@disputed)';
    $stmt = $pdo->prepare($sql);
    $stmt->bindParam(':no', $customerNumber, PDO::PARAM_INT);
    $stmt->execute();
    $stmt->closeCursor();
    // execute the second query to get values from OUT parameter
    $r = $pdo->query("SELECT @shipped,@canceled,@resolved,@disputed")
         ->fetch(PDO::FETCH_ASSOC);
    if ($r) {
      printf('Shipped: %d, Canceled: %d, Resolved: %d, Disputed: %d',
        $r['@shipped'],
        $r['@canceled'],
        $r['@resolved'],
        $r['@disputed']);
    }
  } catch (PDOException $pe) {
    die("Error occurred:" . $pe->getMessage());
  }
}
call_sp(141);

上述代碼中，在@符號(hào)之前的用戶定義的變量與數(shù)據(jù)庫(kù)連接相關(guān)聯(lián)，因此它們可用于在調(diào)用之間進(jìn)行訪問(wèn)。

好啦，本次分享就到這里了。

更多關(guān)于MySQL相關(guān)內(nèi)容感興趣的讀者可查看本站專題：《MySQL存儲(chǔ)過(guò)程技巧大全》、《MySQL常用函數(shù)大匯總》、《MySQL日志操作技巧大全》、《MySQL事務(wù)操作技巧匯總》及《MySQL數(shù)據(jù)庫(kù)鎖相關(guān)技巧匯總》

希望本文所述對(duì)大家MySQL數(shù)據(jù)庫(kù)計(jì)有所幫助。

您可能感興趣的文章: