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POForeach not inserting in fields of MySQL
 

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  1. POForeach not inserting in fields of MySQL
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    <p>I have a database with authors, books, subjects, publishers etc.</p> <p>In one of my forms I insert all of the book information and one of the informations are which authors (from the database) wrote the specific book. </p> <p>I have a many-to-many relationship between the author table and the book table with the table between them named <code>book_author</code>. What I do in the book form is insert the authors IDs chosen from a <code>select multiple</code> in php into the <code>book_author</code> table along with the ISBN of the book so every book_ISBN with author_ID combination will be unique in that table (even though I have not set the combination as a primary key because I have no more information in that table).</p> <p>The problem is that my foreach statement will insert in the database only once and also if I have many authors chosen (more than 2 usually) it will not insert anything at all.</p> <p>EDIT: The authors are displayed properly in the <code>select multiple</code></p> <p>I have checked with <code>var_dump()</code> and the array has the correct IDs, example after selecting 2 authors:</p> <p><code>array(2) { [0]=&gt; string(1) "3" [1]=&gt; string(1) "2" }</code></p> <p>I have even checked if each query is produced correctly, same example:</p> <p><code>string(77) "INSERT INTO book_author (book_ISBN, author_ID) VALUES ('87979695faae','3')"</code></p> <p><code>string(77) "INSERT INTO book_author (book_ISBN, author_ID) VALUES ('87979695faae','2')"</code></p> <p>But the problem insists and I have no idea what to do, here is my code:</p> <pre><code>if (!isset($_POST["authors"])){ header("Location: addBook.php"); exit; } var_dump($_POST["authors"]); $authors = $_POST["authors"]; foreach ($authors as $author) { $sqlAuthor = "INSERT INTO book_author (book_ISBN, author_ID) VALUES ('$isbn','$author')"; var_dump($sqlAuthor); mysql_query($sqlAuthor); } </code></pre> <p>My suspicion would be this <code>mysql_query($sqlAuthor);</code> but I'm not sure...</p> <p>EDIT: I used the <code>die</code> function as instructed and this is the error I got </p> <pre><code>Cannot add or update a child row: a foreign key constraint fails (`library`.`book_author`, CONSTRAINT `FK_written1` FOREIGN KEY (`book_ISBN`) REFERENCES `book` (`book_ISBN`)) </code></pre>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USMadison Scodelario
    1. USMadison Scodelario
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. VO
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      1. POForeach not inserting in fields of MySQL
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYou are not fetcing any errors. do `mysql_query($sqlAuthor)or die(mysql_error());`
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      1. POForeach not inserting in fields of MySQL
      1. This table or related slice is empty.
    2. COIs `mysql_query()` returning `false` perhaps?
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      1. POForeach not inserting in fields of MySQL
      1. USJa͢ck
 

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