magento 2.3.4 installation issue in localhost

please use the below solution

vendor/magento/framework/DB/Adapter/Pdo/Mysql.php

line 1846

after line

case 'smallint':

add

case 'smallint unsigned':

and after line

case 'int':

add

case 'int unsigned':

or full method code

protected function _getColumnTypeByDdl($column)
    {
        switch ($column['DATA_TYPE']) {
            case 'bool':
                return Table::TYPE_BOOLEAN;
            case 'tinytext':
            case 'char':
            case 'varchar':
            case 'text':
            case 'mediumtext':
            case 'longtext':
                return Table::TYPE_TEXT;
            case 'blob':
            case 'mediumblob':
            case 'longblob':
                return Table::TYPE_BLOB;
            case 'tinyint':
            case 'smallint':
            case 'smallint unsigned':
                return Table::TYPE_SMALLINT;
            case 'mediumint':
            case 'int':
            case 'int unsigned':
                return Table::TYPE_INTEGER;
            case 'bigint':
                return Table::TYPE_BIGINT;
            case 'datetime':
                return Table::TYPE_DATETIME;
            case 'timestamp':
                return Table::TYPE_TIMESTAMP;
            case 'date':
                return Table::TYPE_DATE;
            case 'float':
                return Table::TYPE_FLOAT;
            case 'decimal':
            case 'numeric':
                return Table::TYPE_DECIMAL;
        }
    }

This worked for me. Hope this works for you as well, Thank You.