如何從字符中提取MySQL數據庫中的文本？

Question

我需要從MySQL數據庫中順序提取字符到所需的數字（而不是整個文本一次存儲爲長文本或文本）。我正在使用PHP。我該怎麼做？

Answer 1

http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_substr

mysql> SELECT SUBSTRING('Quadratically',5); 
     -> 'ratically' 
mysql> SELECT SUBSTRING('foobarbar' FROM 4); 
     -> 'barbar' 
mysql> SELECT SUBSTRING('Quadratically',5,6); 
     -> 'ratica' 
mysql> SELECT SUBSTRING('Sakila', -3); 
     -> 'ila' 
mysql> SELECT SUBSTRING('Sakila', -5, 3); 
     -> 'aki' 
mysql> SELECT SUBSTRING('Sakila' FROM -4 FOR 2); 
     -> 'ki' 


<?php 
$con = mysql_connect("localhost","peter","abc123"); 
if (!$con) 
    { 
    die('Could not connect: ' . mysql_error()); 
    } 

mysql_select_db("my_db", $con); 

// select first 5 characters from full_name column in table Persons 
$result = mysql_query("SELECT SUBSTRING(full_name, 1, 5) AS partialName FROM Persons"); 

while($row = mysql_fetch_array($result)) 
    { 
    echo $row['partialName']; 
    echo "<br />"; 
    } 

mysql_close($con); 
?> 

Answer 2

您應該使用SQL函數Substring。該鏈接有一堆關於如何去做的例子。您只需調用SQL查詢就像在PHP中使用其他語言一樣。

Answer 3

您可以使用SUBSTRING或SUBSTR方法（它們是相同的）。

mysql> SELECT SUBSTRING('Quadratically',5); 
     -> 'ratically' 
mysql> SELECT SUBSTRING('foobarbar' FROM 4); 
     -> 'barbar' 
mysql> SELECT SUBSTRING('Quadratically',5,6); 
     -> 'ratica' 
mysql> SELECT SUBSTRING('Sakila', -3); 
     -> 'ila' 
mysql> SELECT SUBSTRING('Sakila', -5, 3); 
     -> 'aki' 
mysql> SELECT SUBSTRING('Sakila' FROM -4 FOR 2); 
     -> 'ki' 

Answer 4

只需使用SUBSTRING即可。

SELECT SUBSTRING(column,80) as string FROM TABLE 

http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_substr