在MySQL中从XML中提取值

Question

我正在尝试从XML中提取值。当XML带有属性时，我遇到了问题。就像以下存储过程：

DELIMITER $$
DROP PROCEDURE IF EXISTS `excel`.`insert_items` $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `insert_items`()
BEGIN
SET @xml = '<items><item>
        <value columntype="0">Single Line Text_01</value>
    <value columntype="1">Single Line Text_12341</value>
    <value columntype="2">Single Line Text_21</value>
    <value columntype="3">Single Line Text_31</value>
    <value columntype="4">Single Line Text_41</value>
    </item>
</items>';
SELECT @columntype, ExtractValue(@xml, 'items/item/value[items/item/value/@columntype=0]');    
END $$
DELIMITER ;

- MRX

---

这里提取的问题是什么？ - thar45

Answer 1

要获取具有属性 columntype="0" 的元素的值

SELECT ExtractValue(@xml, 'items/item/value[@columntype=0]') value;

输出：

|               VALUE |
-----------------------
| Single Line Text_01 |

SQLFiddle

- peterm

---

如果我有以下XML格式的代码： Single Line Text_01 Single Line Text_12341 Single Line Text_21 Single Line Text_31 Single Line Text_41 在这种情况下，如何逐个提取这些值？ - Ali

Answer 2

以下代码将打印出columntype和value的值：

 DELIMITER $$
    DROP PROCEDURE IF EXISTS `TEST`$$
    CREATE DEFINER=`root`@`localhost` PROCEDURE `TEST`(IN XMLINPUT TEXT)
    BEGIN
    DECLARE VALUECOUNT INT UNSIGNED;
    DECLARE VALUE INT UNSIGNED;
    DECLARE I INT UNSIGNED DEFAULT 1;
    SET VALUECOUNT:=EXTRACTVALUE(XMLINPUT, 'COUNT(/items/item/value)');
    SELECT VALUECOUNT; -- print 5
    WHILE (I <= VALUECOUNT) DO 
        SELECT EXTRACTVALUE(XMLINPUT, '/items/item/value[$I]/@columntype[1]'); -- will print columntype tag
        SELECT EXTRACTVALUE(XMLINPUT, '/items/item/value[$I]'); -- will print value tag     
    SET I:= I+1;
    END WHILE;

    END$$DELIMITER ;

- 2787184