It should be noted that PDO::FETCH_CLASS will call the constructor *after* setting the values (or calling __set).
下列常量由此扩展定义,且仅在此扩展编译入 PHP 或在运行时动态载入时可用。
PDO::PARAM_BOOL
(int)
PDO::PARAM_NULL
(int)
PDO::PARAM_INT
(int)
PDO::PARAM_STR
(int)
PDO::PARAM_STR_NATL
(int)
PDO::PARAM_STR_CHAR
(int)
PDO::PARAM_LOB
(int)
PDO::PARAM_STMT
(int)
PDO::PARAM_INPUT_OUTPUT
(int)
PDO::FETCH_DEFAULT
(int)
PDO::FETCH_LAZY
(int)
PDO::FETCH_LAZY
创建用来访问的对象变量名。在 PDOStatement::fetchAll() 中无效。
PDO::FETCH_ASSOC
(int)
PDO::FETCH_ASSOC
每个列名只返回一个值。
PDO::FETCH_NAMED
(int)
PDO::FETCH_ASSOC
每个列名 返回一个包含值的数组。
PDO::FETCH_NUM
(int)
PDO::FETCH_BOTH
(int)
PDO::FETCH_OBJ
(int)
PDO::FETCH_BOUND
(int)
PDO::FETCH_COLUMN
(int)
PDO::FETCH_CLASS
(int)
注意: 如果所请求的类中不存在该属性,则调用 __set() 魔术方法
PDO::FETCH_INTO
(int)
PDO::FETCH_FUNC
(int)
PDO::FETCH_GROUP
(int)
PDO::FETCH_COLUMN
或 PDO::FETCH_KEY_PAIR
一起使用。
PDO::FETCH_UNIQUE
(int)
PDO::FETCH_KEY_PAIR
(int)
PDO::FETCH_CLASSTYPE
(int)
PDO::FETCH_SERIALIZE
(int)
PDO::FETCH_INTO
,但是以序列化的字符串表示对象。如果设置此标志,则类的构造函数永远不会被调用。自
PHP 8.1.0 起弃用。
PDO::FETCH_PROPS_LATE
(int)
PDO::ATTR_AUTOCOMMIT
(int)
false
,PDO 将试图禁用自动提交以便数据库连接开始一个事务。
PDO::ATTR_PREFETCH
(int)
PDO::ATTR_TIMEOUT
(int)
PDO::ATTR_ERRMODE
(int)
PDO::ATTR_SERVER_VERSION
(int)
PDO::ATTR_CLIENT_VERSION
(int)
PDO::ATTR_SERVER_INFO
(int)
PDO::ATTR_CONNECTION_STATUS
(int)
PDO::ATTR_CASE
(int)
PDO::CASE_*
的常量强制列名为指定的大小写。
PDO::ATTR_CURSOR_NAME
(int)
PDO::ATTR_CURSOR
(int)
PDO::CURSOR_FWDONLY
和 PDO::CURSOR_SCROLL
。一般为 PDO::CURSOR_FWDONLY
,除非确实需要一个可滚动游标。
PDO::ATTR_DRIVER_NAME
(int)
示例 #1 使用 PDO::ATTR_DRIVER_NAME
的例子
<?php
if ($db->getAttribute(PDO::ATTR_DRIVER_NAME) == 'mysql') {
echo "Running on mysql; doing something mysql specific here\n";
}
?>
PDO::ATTR_ORACLE_NULLS
(int)
PDO::ATTR_PERSISTENT
(int)
PDO::ATTR_STATEMENT_CLASS
(int)
PDO::ATTR_FETCH_CATALOG_NAMES
(int)
PDO::ATTR_FETCH_TABLE_NAMES
(int)
PDO::ATTR_STRINGIFY_FETCHES
(int)
PDO::ATTR_MAX_COLUMN_LEN
(int)
PDO::ATTR_DEFAULT_FETCH_MODE
(int)
PDO::ATTR_EMULATE_PREPARES
(int)
PDO::ATTR_DEFAULT_STR_PARAM
(int)
PDO::PARAM_STR_NATL
和 PDO::PARAM_STR_CHAR
。
自 PHP 7.2.0 起可用
PDO::ERRMODE_SILENT
(int)
PDO::ERRMODE_WARNING
(int)
E_WARNING
消息。关于此属性的更多信息请参见 错误与错误处理。
PDO::ERRMODE_EXCEPTION
(int)
PDO::CASE_NATURAL
(int)
PDO::CASE_LOWER
(int)
PDO::CASE_UPPER
(int)
PDO::NULL_NATURAL
(int)
PDO::NULL_EMPTY_STRING
(int)
PDO::NULL_TO_STRING
(int)
PDO::FETCH_ORI_NEXT
(int)
PDO::FETCH_ORI_PRIOR
(int)
PDO::FETCH_ORI_FIRST
(int)
PDO::FETCH_ORI_LAST
(int)
PDO::FETCH_ORI_ABS
(int)
PDO::FETCH_ORI_REL
(int)
PDO::CURSOR_FWDONLY
(int)
PDO::CURSOR_SCROLL
(int)
PDO::FETCH_ORI_*
常量来控制结果集中获取的行。
PDO::ERR_NONE
(string)
PDO::PARAM_EVT_ALLOC
(int)
PDO::PARAM_EVT_FREE
(int)
PDO::PARAM_EVT_EXEC_PRE
(int)
PDO::PARAM_EVT_EXEC_POST
(int)
PDO::PARAM_EVT_FETCH_PRE
(int)
PDO::PARAM_EVT_FETCH_POST
(int)
PDO::PARAM_EVT_NORMALIZE
(int)
PDO::SQLITE_DETERMINISTIC
(int)
It should be noted that PDO::FETCH_CLASS will call the constructor *after* setting the values (or calling __set).
Reference to all the PDO::MYSQL_* constants is available in MySQL's documentation for the driver here: https://dev.mysql.com/doc/connectors/en/apis-php-pdo-mysql.html
Such as the ones I was looking for PDO::MYSQL_ATTR_SSL_CA and PDO::MYSQL_ATTR_SSL_CAPATH which are not listed on this page.
PDO::PARAM_STR_CHAR and PDO::PARAM_STR_NATL must be combined with PDO::PARAM_STR using bitwise-OR for parameter binding.
These flags control value quoting (e.g. PDO::quote) and, in some situations (see below), parameter binding (e.g. PDO::bindParam, PDO::bindValue) to prefix string literals with N'' as defined in SQL-92. As of PHP 7.3, only dblib and mysql support these flags. For the mysql driver, the flags only affect parameter binding when PDO::ATTR_EMULATE_PREPARES is true (the default).
MySQL and MariaDB interpret string literals prefixed with N as being utf8 (not utf8mb4) regardless of `SET NAMES` or the charset parameter. This can cause problems if the database/table/column charset is not utf8. For example, in a database using utf8mb4, the query "SELECT * FROM table WHERE col = :param" and bindValue(":param", "\u{1F600}", PDO::PARAM_STR | PDO::PARAM_STR_NATL) will cause "PDOException: SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (utf8mb4_general_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '='". Using PDO::PARAM_STR without PDO::PARAM_STR_NATL and ensuring the charset DSN parameter is set correctly can avoid this issue.
See:
https://wiki.php.net/rfc/extended-string-types-for-pdo
https://mariadb.com/kb/en/library/string-literals/
https://dev.mysql.com/doc/refman/8.0/en/string-literals.html
PDO::FETCH_UNIQUE not only fetches the unique values, it also uses the first SQL column as array key result, what is very useful for create quickly an index, eg :
<?php
$sql = <<<SQL
SELECT ALL
c1, -- For result indexing
c1, c2
FROM (
VALUES
ROW('ID-1', 'Value 1'),
ROW('ID-2', 'Value 2a'),
ROW('ID-2', 'Value 2b'),
ROW('ID-3', 'Value 3')
) AS t (c1, c2);
SQL;
$result = $pdo->query($sql);
print_r($result->fetchAll(PDO::FETCH_UNIQUE));
/*
Gives :
ID-1 => [c1 => ID-1, c2 => Value 1]
ID-2 => [c1 => ID-2b, c2 => Value 2b]
ID-3 => [c1 => ID-3, c2 => Value 3]
*/
?>
Default value for \PDO::ATTR_TIMEOUT is 30 seconds.
Ref.: https://github.com/php/php-src/blob/PHP-7.1.0/ext/pdo_mysql/mysql_driver.c#L600
Reference for PDO MySQL constants Todd mentioned have moved to here: /manual/en/ref.pdo-mysql.php
This includes documentation on constants like PDO::MYSQL_ATTR_SSL_CA, PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT, and more.
When you use REAL type column on SQLite, your setting of pdo parameter of bindValue() is PDO::PARAM_STR.
'''
$stmt->bindValue(':elapse_time', $e_time, PDO::PARAM_STR);
'''