Yii2.0 reason increment primary keys always query string analysis

【Background of the project】

Recently doing a restful style of the project, we found json data tables returned id is always the string type, but another table id is always int. I.e., the data types are returned.

 

[The Reason]

In yii \ getColumnPhpType function db \ Schema class, this function determines the type out of the final data, as follows:

    /**
     * Extracts the PHP type from abstract DB type.
     * @param ColumnSchema $column the column schema information
     * @return string PHP type name
     */
    protected function getColumnPhpType($column)
    {
        static $typeMap = [
            // abstract type => php type
            self::TYPE_TINYINT => 'integer',
            self::TYPE_SMALLINT => 'integer',
            self::TYPE_INTEGER => 'integer',
            self::TYPE_BIGINT => 'integer',
            self::TYPE_BOOLEAN => 'boolean',
            self::TYPE_FLOAT => 'double',
            self::TYPE_DOUBLE => 'double',
            self::TYPE_BINARY => 'resource',
            self::TYPE_JSON => 'array',
        ];
        if (isset($typeMap[$column->type])) {
            if ($column->type === 'bigint') {
                return PHP_INT_SIZE === 8 && !$column->unsigned ? 'integer' : 'string';-> type === 'Integer'$ column(ELSEIF
            }// field type determined here) {
                 Return PHP_INT_SIZE ===. 4 && $ column ? -> unsigned 'String': 'Integer' ; // field type determined here 
            } 

            return  $ typeMap [ $ column -> type]; 
        } 

        return 'String' ; 
    }

Conclusion: If PHP_INT_SIZE DB table is 4 and the corresponding column is unsigned int, then returns the string type in accordance with the interpretation php.net:. PHP does not support unsigned integer.