MySQL全面瓦解之查詢的正則匹配詳解
阿新 • • 發佈：2020-11-12
概述
上一章 查詢的過濾條件，我們瞭解了MySQL可以通過 like % 萬用字元來進行模糊匹配。同樣的，它也支援其他正則表示式的匹配，我們在MySQL中使用 REGEXP 操作符來進行正則表示式匹配。用法和like相
似，但又強大很多，能夠實現一些很特殊的、複雜的規則匹配。正則表示式使用REGEXP命令進行匹配時，如果符合返回1，不符合返回0。如果 預設不加任何匹配規則REGEXP相當於like '%%'。在前面加上NOT（NOT REGEXP）相當於NOT LIKE。
匹配模式分析
下面有個表格 ，羅列了可應用於 REGEXP 操作符中正則匹配模式，描述相對比較詳細了，後面我們一個一個來測試。
|
匹配模式 |
描述 |
|
^ |
匹配輸入字串的開始位置。如果設定了REGEXP物件的 Multiline 屬性，^ 也匹配 '\n' 或 '\r' 之後的位置。 |
|
$ |
匹配輸入字串的結束位置。如果設定了REGEXP物件的 Multiline 屬性，$ 也匹配 '\n' 或 '\r' 之前的位置。 |
|
. |
匹配除 "\n" 之外的任何單個字元。要匹配包括 '\n' 在內的任何字元，請使用 '[.\n]' 的模式。 |
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[….] |
字元集合。匹配所包含的任意一個字元。例如， '[abc]' 可以匹配 "plain" 中的 'a'。 |
|
[^...] |
非匹配字元集合。匹配未包含的任意字元。例如， '[^abc]' 可以匹配 "plain" 中的'p'。 |
|
[n-m] |
匹配m到n之間的任意單個字元，例如[0-9],[a-z],[A-Z] |
|
* |
匹配前面的子表示式零次或多次。例如，a* 能匹配 "a" 以及 "ab"。* 等價於{0,}。 |
|
+ |
匹配前面的子表示式一次或多次。例如，'a+' 能匹配 "ab" 以及 "abc"，但不能匹配 "a"。+ 等價於 {1,}。 |
|
? |
匹配前面的子表示式一次或多次。例如，'a?' 能匹配 "ab" 以及 "a"。? 等價於 {0,1}。 |
|
a1| a2|a3 |
匹配 a1 或 a2 或 a3。例如，'z|food' 能匹配 "z" 或 "food"。'(z|f)ood' 則匹配 "zood" 或 "food"。 |
|
{n} |
n 是一個非負整數。匹配確定的 n 次。例如，'o{2}' 不能匹配 "Bob" 中的 'o'，但是能匹配 "food" 中的兩個 o。 |
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{n,} |
匹配前面的子表示式n次到多次。例如，'o{2,}' 不僅能匹配 "food" ，也能匹配 "foood"。 |
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{n,m} |
n 和 m 均為非負整數，其中n <= m。最少匹配 n 次且最多匹配 m 次。 |
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{,m} |
匹配前面的子表示式0次到m次 |
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(….) |
元素組合，即將模式元素組成單一元素，例如（do）*意思是匹配0個多或多個do |
匹配模式^
從字串首部分進行匹配，這邊匹配s開頭的，匹配符合返回1，不符合返回0。應用到表中，既符合返回匹配到的資料。
mysql> select 'selina' REGEXP '^s'; +----------------------+ | 'selina' REGEXP '^s' | +----------------------+ | 1 | +----------------------+ 1 row in set mysql> select 'aelina' REGEXP '^s'; +----------------------+ | 'aelina' REGEXP '^s' | +----------------------+ | 0 | +----------------------+ 1 row in set
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 5 rows in set mysql> select * from user2 where name REGEXP '^s'; +----+--------+-----+---------+-----+ | id | name | age | address | sex | +----+--------+-----+---------+-----+ | 3 | sol | 21 | xiamen | 0 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+---------+-----+ 2 rows in set
匹配模式$
從字串尾部進行匹配，這邊匹配名稱以d結尾的資料。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 5 rows in set mysql> select * from user2 where name REGEXP 'd$'; +----+-------+-----+---------+-----+ | id | name | age | address | sex | +----+-------+-----+---------+-----+ | 1 | brand | 21 | fuzhou | 1 | +----+-------+-----+---------+-----+ 1 row in set
匹配模式.
. 是匹配任意單個字元，下面指令碼匹配 n並且後面帶一個任意字元的條件
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 5 rows in set mysql> select * from user2 where name REGEXP 'n.'; +----+--------+-----+---------+-----+ | id | name | age | address | sex | +----+--------+-----+---------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+---------+-----+ 3 rows in set
匹配模式[...]
指匹配括號內的任意單個字元，只要有一個字元符合條件即可。下面例子能匹配到b、w、z的 只有brand、weng 兩個名稱。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 5 rows in set mysql> select * from user2 where name REGEXP [bwz]; 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '[bwz]' at line 1 mysql> select * from user2 where name REGEXP '[bwz]'; +----+-------+-----+---------+-----+ | id | name | age | address | sex | +----+-------+-----+---------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 4 | weng | 33 | guizhou | 1 | +----+-------+-----+---------+-----+ 2 rows in set
匹配模式[^...]
[^...]取反的意思，指匹配未包含的任意字元。例如， '[^brand]' 可以匹配 "helen" 中的'h'，"sol" 的 "s"，"weng" 的 "w"，"selina" 的 "s"，但無法匹配"brand"，所以被過濾了。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 5 rows in set mysql> select * from user2 where name REGEXP '[^brand]'; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 4 rows in set
匹配模式[n-m]
匹配m到n之間的任意單個字元，例如[0-9],[A-Z]，下方程式碼中，任何元素不在a - e之間的"sol" 被過濾了。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 5 rows in set mysql> select * from user2 where name REGEXP '[a-e]'; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 4 rows in set
匹配模式 *
匹配前面的子表示式零次或多次。例如，a* 能匹配 "a" 以及 "ab"。* 等價於{0,}。 下面的 "e*g" 可以匹配的只有 "weng" 這個名稱。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 5 rows in set mysql> select * from user2 where name REGEXP 'e*g'; +----+------+-----+---------+-----+ | id | name | age | address | sex | +----+------+-----+---------+-----+ | 4 | weng | 33 | guizhou | 1 | +----+------+-----+---------+-----+ 1 row in set
匹配模式 +
匹配前面的子表示式一次或多次。例如，'a+' 能匹配 "ab" 以及 "abc"，但不能匹配 "a"。+ 等價於 {1,}。如下方的指令碼，符合條件的是1到多個的n加上一個d的組合，只有 "brand" 和 "annd" 符合。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | | 6 | anny | 23 | shanghai | 0 | | 7 | annd | 24 | shanghai | 1 | +----+--------+-----+----------+-----+ 7 rows in set mysql> select * from user2 where name REGEXP 'n+d'; +----+-------+-----+----------+-----+ | id | name | age | address | sex | +----+-------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 7 | annd | 24 | shanghai | 1 | +----+-------+-----+----------+-----+ 2 rows in set
匹配模式 ?
匹配前面的子表示式一次或多次。例如，'a?' 能匹配 "ab" 以及 "a"。? 等價於 {0,1}。e為1個或者0個，後面再用 l 限制，所以符合的只有三個。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | | 6 | anny | 23 | shanghai | 0 | | 7 | annd | 24 | shanghai | 1 | +----+--------+-----+----------+-----+ 7 rows in set mysql> select * from user2 where name REGEXP 'e?l'; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 5 | selina | 25 | NULL | 0 | +----+--------+-----+----------+-----+ 3 rows in set
匹配模式 a1| a2|a3
匹配 a1 或 a2 或 a3。例如下方，'nn|en' 能分別匹配到 "anny" 、"annd" 和 "helen"、"weng"。
mysql> select * from user2; +----+--------+-----+----------+-----+ | id | name | age | address | sex | +----+--------+-----+----------+-----+ | 1 | brand | 21 | fuzhou | 1 | | 2 | helen | 20 | quanzhou | 0 | | 3 | sol | 21 | xiamen | 0 | | 4 | weng | 33 | guizhou | 1 | | 5 | selina | 25 | NULL | 0 | | 6 | anny | 23 | shanghai | 0 | | 7 | annd | 24 | shanghai | 1 | +----+--------+-----+----------+-----+ 7 rows in set mysql> select * from user2 where name REGEXP 'nn|en'; +----+-------+-----+----------+-----+ | id | name | age | address | sex | +----+-------+-----+----------+-----+ | 2 | helen | 20 | quanzhou | 0 | | 4 | weng | 33 | guizhou | 1 | | 6 | anny | 23 | shanghai | 0 | | 7 | annd | 24 | shanghai | 1 | +----+-------+-----+----------+-----+ 4 rows in set
匹配模式 {n} {n,} {n,m} {,m}
n 和 m 均為非負整數，其中n <= m。最少匹配 n 次且最多匹配 m 次。m為空代表>=n的任意數，n為空代表0。
mysql> select * from user2;
+----+--------+-----+----------+-----+
| id | name | age | address | sex |
+----+--------+-----+----------+-----+
| 1 | brand | 21 | fuzhou | 1 |
| 2 | helen | 20 | quanzhou | 0 |
| 3 | sol | 21 | xiamen | 0 |
| 4 | weng | 33 | guizhou | 1 |
| 5 | selina | 25 | NULL | 0 |
| 6 | anny | 23 | shanghai | 0 |
| 7 | annd | 24 | shanghai | 1 |
+----+--------+-----+----------+-----+
7 rows in set
mysql> select * from user2 where name REGEXP 'n{2}';
+----+------+-----+----------+-----+
| id | name | age | address | sex |
+----+------+-----+----------+-----+
| 6 | anny | 23 | shanghai | 0 |
| 7 | annd | 24 | shanghai | 1 |
+----+------+-----+----------+-----+
2 rows in set
mysql> select * from user2 where name REGEXP 'n{1,2}';
+----+--------+-----+----------+-----+
| id | name | age | address | sex |
+----+--------+-----+----------+-----+
| 1 | brand | 21 | fuzhou | 1 |
| 2 | helen | 20 | quanzhou | 0 |
| 4 | weng | 33 | guizhou | 1 |
| 5 | selina | 25 | NULL | 0 |
| 6 | anny | 23 | shanghai | 0 |
| 7 | annd | 24 | shanghai | 1 |
+----+--------+-----+----------+-----+
6 rows in set
mysql> select * from user2 where name REGEXP 'l{1,}';
+----+--------+-----+----------+-----+
| id | name | age | address | sex |
+----+--------+-----+----------+-----+
| 2 | helen | 20 | quanzhou | 0 |
| 3 | sol | 21 | xiamen | 0 |
| 5 | selina | 25 | NULL | 0 |
+----+--------+-----+----------+-----+
3 rows in set
匹配模式(...)
假設括號內容為abc，則是將abc作為一個整體去匹配，符合這個規則的資料被過濾出來。下面以an為例子，配合上面學過的知識。
mysql> select * from user2;
+----+--------+-----+----------+-----+
| id | name | age | address | sex |
+----+--------+-----+----------+-----+
| 1 | brand | 21 | fuzhou | 1 |
| 2 | helen | 20 | quanzhou | 0 |
| 3 | sol | 21 | xiamen | 0 |
| 4 | weng | 33 | guizhou | 1 |
| 5 | selina | 25 | NULL | 0 |
| 6 | anny | 23 | shanghai | 0 |
| 7 | annd | 24 | shanghai | 1 |
+----+--------+-----+----------+-----+
7 rows in set
mysql> select * from user2 where name REGEXP '(an)+';
+----+-------+-----+----------+-----+
| id | name | age | address | sex |
+----+-------+-----+----------+-----+
| 1 | brand | 21 | fuzhou | 1 |
| 6 | anny | 23 | shanghai | 0 |
| 7 | annd | 24 | shanghai | 1 |
+----+-------+-----+----------+-----+
3 rows in set
mysql> select * from user2 where name REGEXP '(ann)+';
+----+------+-----+----------+-----+
| id | name | age | address | sex |
+----+------+-----+----------+-----+
| 6 | anny | 23 | shanghai | 0 |
| 7 | annd | 24 | shanghai | 1 |
+----+------+-----+----------+-----+
2 rows in set
mysql> select * from user2 where name REGEXP '(an).*d{1,2}';
+----+-------+-----+----------+-----+
| id | name | age | address | sex |
+----+-------+-----+----------+-----+
| 1 | brand | 21 | fuzhou | 1 |
| 7 | annd | 24 | shanghai | 1 |
+----+-------+-----+----------+-----+
2 rows in set
匹配特殊字元 \\
正則表示式語言由具有特定含義的特殊字元構成。我們已經看到.、 []、|、*、+ 等， 那我們是怎麼匹配這些字元的。如下示例，我們使用 \\ 來匹配特殊字元，\\為前導， \\-表示查詢-， \\.表示查詢.。
mysql> select * from user3; +----+------+-------+ | id | age | name | +----+------+-------+ | 1 | 20 | brand | | 2 | 22 | sol | | 3 | 20 | helen | | 4 | 19.5 | diny | +----+------+-------+ 4 rows in set mysql> select * from user3 where age REGEXP '[0-9]+\\.[0-9]+'; +----+------+------+ | id | age | name | +----+------+------+ | 4 | 19.5 | diny | +----+------+------+ 1 row in set
總結
1.當我們需要用正則匹配資料的時候，可以使用REGEXP和NOT REGEXP操作符(類似LIKE和NOT LIKE)；
2.REGEXP預設不區分大小寫，可以使用BINARY關鍵詞強制區分大小寫； WHERE NAME REGEXP BINARY ‘^[A-Z]';
3.REGEXP預設是部分匹配原則，即有一個匹配上則返回真。例如：SELECT 'A123' REGEXP BINARY '[A-Z]'，返回的是1;
4、如果使用 () 進行匹配，則是將括號內部的內容當作整體去匹配，比如 (ABC)，則需要匹配整個ABC。
5、這邊只是看介紹了正則的基礎知識，想要更為透徹的瞭解可以參考 正則教程 ，我覺得寫的不錯。
到此這篇關於MySQL全面瓦解之查詢的正則匹配詳解的文章就介紹到這了,更多相關MySQL查詢的正則匹配內容請搜尋我們以前的文章或繼續瀏覽下面的相關文章希望大家以後多多支援我們！