MySQL：如何將值分成3個可能的空間部分

我有一列可以有1,2或3個空格分開的部分。我需要提取每個部分「如果」它存在（字符串將始終包含至少第一部分）。MySQL：如何將值分成3個可能的空間部分

實施例：

1: Apple 
2: Apple Orange 
3: Apple Pear lemon 


|1| Apple    | Apple |  |  | 
|2| Apple Orange  | Apple | Orange |  | 
|3| Pear lemon Orange | Pear | lemon | Orange |

我可以提取第一部分和第三部分（但如果只有一個部件此插入在第三列中的值相同）。

SELECT 
`productCode`, 
SUBSTRING_INDEX(`productCode`, ' ', 1), 
SUBSTRING_INDEX(`productCode`, ' ', -1) 
FROM tblSubmissionProducts;

來源

2016-04-25 nads

你可以用它來分割字符串：

SELECT 
    REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 1)),' ',1)) AS n1, 
    REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 2)),' ',1)) AS n2, 
    REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 3)),' ',1)) AS n3, 
    REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 4)),' ',1)) AS n4;

樣品

MariaDB [(none)]> SELECT 
    -> REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 1)),' ',1)) AS n1, 
    -> REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 2)),' ',1)) AS n2, 
    -> REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 3)),' ',1)) AS n3, 
    -> REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX('This is a Test', ' ', 4)),' ',1)) AS n4; 
+------+----+----+------+ 
| n1 | n2 | n3 | n4 | 
+------+----+----+------+ 
| This | is | a | Test | 
+------+----+----+------+ 
1 row in set (0.00 sec) 

MariaDB [(none)]>

改變答案

SELECT 
    TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple', ' '), ' ', 1)),' ',1))) AS n1, 
    TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple', ' '), ' ', 2)),' ',1))) AS n2, 
    TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple', ' '), ' ', 3)),' ',1))) AS n1;

更好樣品

MariaDB [(none)]> SELECT 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple', ' '), ' ', 1)),' ',1))) AS n1, 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple', ' '), ' ', 2)),' ',1))) AS n2, 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple', ' '), ' ', 3)),' ',1))) AS n1; 
+-------+----+----+ 
| n1 | n2 | n1 | 
+-------+----+----+ 
| Apple | | | 
+-------+----+----+ 
1 row in set (0.00 sec) 

MariaDB [(none)]> 
MariaDB [(none)]> SELECT 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple Orange', ' '), ' ', 1)),' ',1))) AS n1, 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple Orange', ' '), ' ', 2)),' ',1))) AS n2, 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Apple Orange', ' '), ' ', 3)),' ',1))) AS n1; 
+-------+--------+----+ 
| n1 | n2  | n1 | 
+-------+--------+----+ 
| Apple | Orange | | 
+-------+--------+----+ 
1 row in set (0.00 sec) 

MariaDB [(none)]> 
MariaDB [(none)]> SELECT 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Pear lemon Orange', ' '), ' ', 1)),' ',1))) AS n1, 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Pear lemon Orange', ' '), ' ', 2)),' ',1))) AS n2, 
    -> TRIM(REVERSE(SUBSTRING_INDEX(REVERSE (SUBSTRING_INDEX(CONCAT('Pear lemon Orange', ' '), ' ', 3)),' ',1))) AS n1; 
+------+-------+--------+ 
| n1 | n2 | n1  | 
+------+-------+--------+ 
| Pear | lemon | Orange | 
+------+-------+--------+ 
1 row in set (0.00 sec) 

MariaDB [(none)]>

來源

2016-04-25 13:26:10

嗨貝恩德，這是偉大的！但是有沒有辦法不復制字符串，如果只有一個部分？所以在示例1中：Apple：所有列中都顯示相同的字符串： + -------- + ---------- + ------ + -------- + | n1 | n2 | n3 | n4 | + -------- + ---------- + ------ + -------- + |蘋果|蘋果|蘋果|蘋果| + -------- + ---------- + ------ + -------- + – nads

@nads - 如果在我的答案中添加了一個示例 –

這就是輝煌！謝謝Bernd。這工作完美。 – nads

它應該工作

SELECT product_code, 
     SUBSTRING_INDEX(product_code, ' ',1), 
     SUBSTRING_INDEX(SUBSTRING_INDEX(product_code, ' ',2),' ',-1), 
     SUBSTRING_INDEX(product_code, ' ',-1) 
FROM tblSubmissionProducts

來源

2016-04-25 13:31:01

MySQL：如何將值分成3個可能的空間部分

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