Locate all datetime fields that should be date fields.

check-for-zero-time-values.php

<?php

/**
 * This fairly basic script will connect to a MySQL database and check all timestamp fields
 * for zero time values. It will log the results to the console.
 *
 * The purpose of this is to highlight fields that should be a DATE field instead of a
 * DATETIME field.
 *
 * usage:
 * php check-for-zero-time-values.php <host> <port> <schema> <user> <password> [<exceptions>]
 */
$host = $argv[1];
$port = $argv[2];
$schema = $argv[3];
$user = $argv[4];
$password = $argv[5];
$exceptions = explode(',', $argv[6] ?? '');

$log = function(string $level, string $message): void
{
    echo sprintf("[%s] %s: %s\n", date('Y-m-d H:i:s'), strtoupper($level), $message);
};

$initConnection = function() use ($log, $host, $port, $schema, $user, $password): \PDO
{
    $log(
        'info',
        sprintf(
            'Attempting to create database connection to host %s on port %s for database %s',
            $host,
            $port,
            $schema
        )
    );

    try {
        return new \PDO(
            sprintf(
                "mysql:host=%s;port=%s;dbname=%s;",
                $host,
                $port,
                $schema
            ),
            $user,
            $password
        );
    } catch (\PDOException $e) {
        $log('error', 'Database connection failed: ' . $e->getMessage());
    }
};

$connection = $initConnection();

$getAllTimestampFields = function() use ($connection, $schema): array
{
    $query = <<<SQL
        select 
            col.table_schema as schemaName,
            col.table_name as tableName, 
            col.column_name as columnName
        from information_schema.columns col
        join information_schema.tables tab on 
            tab.table_schema = col.table_schema
            and tab.table_name = col.table_name
            and tab.table_type = 'BASE TABLE'
        where 
            col.data_type in ('date', 'datetime', 'timestamp')
        and 
            col.table_schema not in ('information_schema', 'sys', 'performance_schema', 'mysql')
        and 
            col.table_schema = '$schema'
        order by 
            col.table_schema, col.table_name, col.ordinal_position;
SQL;

    return $connection->query($query)->fetchAll(\PDO::FETCH_ASSOC);
};

$checkForZeroTimeValues = function(array $tablesAndFields) use($connection, $log, $exceptions): array
{
    $columnsWithOnlyZeroValues = [];

    foreach ($tablesAndFields as $index => $tableField) {
        $columnName = $tableField['columnName'];
        $tableName = $tableField['tableName'];

        if (in_array($columnName, $exceptions)) {
            $log(
                'info',
                sprintf(
                    '%s of %s Skipping column %s in table %s as it is a known timestamp field',
                    $index + 1,
                    count($tablesAndFields),
                    $columnName,
                    $tableName
                )
            );

            continue;
        }

        $log(
            'info',
            sprintf(
                '%s of %s Checking table %s for column %s for only zero time values',
                $index + 1,
                count($tablesAndFields),
                $tableName,
                $columnName
            )
        );

        $zeroTimeValuesQuery = sprintf(
            "select count(*) from $tableName where time(%s) = '00:00:00' and %s is not null",
            $columnName,
            $columnName
        );

        $numberOfRowsWithZeroValues = $connection->query($zeroTimeValuesQuery)->fetchColumn(0);

        $rowCountQuery = sprintf("select count(*) from %s", $tableName);

        $rowCount = $connection->query($rowCountQuery)->fetchColumn(0);

        if ($rowCount === $numberOfRowsWithZeroValues && $rowCount !== 0) {
            $log(
                'warn',
                sprintf(
                    'Table %s has only zero time values in column %s',
                    $tableName,
                    $columnName
                )
            );

            $columnsWithOnlyZeroValues[$tableName][] = $columnName;
        }
    }

    return $columnsWithOnlyZeroValues;
};

$fieldsToInspectForZerodTimes = $getAllTimestampFields();
$tablesThatHaveZeroValues = $checkForZeroTimeValues($fieldsToInspectForZerodTimes);
var_dump($tablesThatHaveZeroValues);