仅在使用限制时显示php和mysql查询结果

Question

In an attempt to learn more php, mysql & json, I downloaded a demo database from: http://www.mysqltutorial.org/wp-content/uploads/downloads/2013/05/mysqlsampledatabase1.zip .

I want to display all customers to echo them out in html table format with edit and delete buttons.

My SQL statement is

"SELECT * FROM customers" 

It returns no results and no errors. However, if I change the SQL statement to

"SELECT * FROM customers LIMIT 11" 

The first 11 of 122 rows are returned. Using a LIMIT of 1-11 will return results while anything 12 or more returns noting.

Can anyone shed some light on this for me please?

UPDATE: Code for assistance.

 <?php $servername = "localhost"; $username = "root"; $password = "root"; $dbname = "classicmodels"; $dbh = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password) or die(mysql_error()); $sql = 'SELECT * FROM customers LIMIT 12' or die(mysql_error()); $stmt = $dbh->prepare($sql); $stmt->execute(); $result = $stmt->fetchAll(PDO::FETCH_ASSOC); echo json_encode($result); die(); ?> 

Thank you in advance,

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Answer 1

The problem is not in your SQL code. If

SELECT * FROM customers LIMIT 11

works correctly, so will

SELECT * FROM customers LIMIT 12

Therefore, there is probably an error in your php code. Either it doesn't handle the 12th record retrieved correctly, or it cannot handle the 12+ limit for some other reason. Could you expand the question with the relevant php code?

Edit

To correctly display special characters, such as the å in Luleå (your 12th record), you must match the character set in the database settings, database connection and output.

For example, if your database collation is UTF-8, make your first query in your script SET NAMES 'utf8' . Then, before printing the json, send a header to the browser (I'm assuming you're outputting to a browser): header('Content-Type: text/json; charset=utf-8');

By configuring your database correctly, the SET NAMES becomes obsolete.

Some helpful guides I found explain this in more detail:

• Change MySQL default character set to UTF-8 in my.cnf?
• https://www.bluebox.net/insight/blog-article/getting-out-of-mysql-character-set-hell

Answer 2

Since you are selecting everything from the table, you may want to change your syntax to:
SELECT * FROM customers (rather then @)
LIMIT x
Where x is your number, this should allow for numbers beyond 12.