How to Bind LIKE Values in PDO Queries Effectively?

Binding LIKE Values in PDO

When using LIKE queries in PDO, it's crucial to understand how to correctly bind the search value to avoid unexpected results.

Binding with Partial Match

To bind a partial match, you can use the following syntax:

SELECT wrd FROM tablename WHERE wrd LIKE :partial

Bind the parameter :partial to the partial value you want to search for. For example, if you have $partial = "somet", you would bind it as:

$stmt->bindParam(':partial', $partial);

Binding with Wildcard

To bind a partial match with a wildcard at the end, you can use either of these methods:

1. PDO-Generated Wildcard:

   Use the following syntax:

   SELECT wrd FROM tablename WHERE wrd LIKE ':partial%'

   Bind the parameter :partial to the partial value without the wildcard.

2. SQL-Generated Wildcard:

   Use the following syntax:

   SELECT wrd FROM tablename WHERE wrd LIKE CONCAT(:partial, '%')

   Bind the parameter :partial to the partial value without the wildcard.

Complex LIKE Queries

If the partial value contains special characters like %, _, or , you need to escape them to prevent unintended results. Use the following code:

$stmt = $db->prepare("SELECT wrd FROM tablename WHERE wrd LIKE :term ESCAPE '+'");
$escaped = str_replace(array('+', '%', '_'), array('++', '+%', '+_'), $var);
$stmt->bindParam(':term', $escaped);

By following these guidelines, you can effectively bind LIKE values in your PDO queries.

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