PHP - Manual: mysqlnd_qc_set_cache_condition
2024-12-23
(PECL mysqlnd_qc >= 1.1.0)
mysqlnd_qc_set_cache_condition — Set conditions for automatic caching
$condition_type
,
mixed
$condition
,
mixed
$condition_option
) : boolSets a condition for automatic caching of statements which do not contain the necessary SQL hints to enable caching of them.
condition_type
Type of the condition. The only allowed value is
MYSQLND_QC_CONDITION_META_SCHEMA_PATTERN
.
condition
Parameter for the condition set with condition_type. Parameter type and structure depend on condition_type
If condition_type equals MYSQLND_QC_CONDITION_META_SCHEMA_PATTERN condition must be a string. The string sets a pattern. Statements are cached if table and database meta data entry of their result sets match the pattern. The pattern is checked for a match with the db and org_table meta data entries provided by the underlying MySQL client server library. Please, check the MySQL Reference manual for details about the two entries. The db and org_table values are concatenated with a dot (.) before matched against condition. Pattern matching supports the wildcards % and _. The wildcard % will match one or many arbitrary characters. _ will match one arbitrary character. The escape symbol is backslash.
condition_option
Option for condition. Type and structure depend on condition_type.
If condition_type equals MYSQLND_QC_CONDITION_META_SCHEMA_PATTERN condition_options is the TTL to be used.
Example #1 mysqlnd_qc_set_cache_condition() example
<?php
/* Cache all accesses to tables with the name "new%" in schema/database "db_example" for 1 second */
if (!mysqlnd_qc_set_cache_condition(MYSQLND_QC_CONDITION_META_SCHEMA_PATTERN, "db_example.new%", 1)) {
die("Failed to set cache condition!");
}
$mysqli = new mysqli("host", "user", "password", "db_example", "port");
/* cached although no SQL hint given */
$mysqli->query("SELECT id, title FROM news");
$pdo_mysql = new PDO("mysql:host=host;dbname=db_example;port=port", "user", "password");
/* not cached: no SQL hint, no pattern match */
$pdo_mysql->query("SELECT id, title FROM latest_news");
/* cached: TTL 1 second, pattern match */
$pdo_mysql->query("SELECT id, title FROM news");
?>
Returns TRUE on success or FALSE on FAILURE.
官方地址:https://www.php.net/manual/en/function.mysqlnd-qc-set-cache-condition.php