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# Database Abstraction Layer

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v5:reference:connection:ifnull

# ifNull

      string ifNull(
             string $fieldToCheck,
             mixed $replacementValue
             )

## Description

The function `ifNull()` returns a database-specific string providing the means to replace a null value with a specified replacement. If the value in the database is not null, the value is not updated. The two parameters are:

1. The field in the table to check.
2. The value to replace the null value with if it is found

## Usage

    /*
     * Assume mysql database connection
    */
    $ifNullString = $db->ifNull('pants_field','chinos');

    /*
     * ifnullString returns 'CASE WHEN pants_field is null
                                  THEN 'chinos'
                                  ELSE pants_field
                                  END ";
    */

    $SQL = "UPDATE attire
               SET pants_field = $ifNullString";

    $db->Execute($SQL);

v5/reference/connection/ifnull.txt · Last modified: 2016/01/16 14:34 by mnewnham

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