Constantele de mai jos sunt definite de această extensie și vor fi disponibile doar dacă această extensie a fost compilată în interiorul PHP, sau a fost încărcată dinamic în timpul rulării.
SQL hint related
Example #1 Using SQL hint constants
The query cache is controlled by SQL hints. SQL hints are used to enable and
disable caching. SQL hints can be used to set the
TTL
of a query.
The SQL hints recognized by the query cache can be manually changed at
compile time. This makes it possible to use
mysqlnd_qc
in environments in which the default
SQL hints are already taken and interpreted by other systems. Therefore
it is recommended to use the SQL hint string constants instead of
manually adding the default SQL hints to the query string.
<?php
/* Use constants for maximum portability */
$query = "/*" . MYSQLND_QC_ENABLE_SWITCH . "*/SELECT id FROM test";
/* Valid but less portable: default TTL */
$query = "/*qc=on*/SELECT id FROM test";
/* Valid but less portable: per statement TTL */
$query = "/*qc=on*//*qc_ttl=5*/SELECT id FROM test";
printf("MYSQLND_QC_ENABLE_SWITCH: %s\n", MYSQLND_QC_ENABLE_SWITCH);
printf("MYSQLND_QC_DISABLE_SWITCH: %s\n", MYSQLND_QC_DISABLE_SWITCH);
printf("MYSQLND_QC_TTL_SWITCH: %s\n", MYSQLND_QC_TTL_SWITCH);
?>
Exemplele de mai sus vor afișa:
MYSQLND_QC_ENABLE_SWITCH: qc=on MYSQLND_QC_DISABLE_SWITCH: qc=off MYSQLND_QC_TTL_SWITCH: qc_ttl=
MYSQLND_QC_ENABLE_SWITCH
(string)
MYSQLND_QC_DISABLE_SWITCH
(string)
mysqlnd_qc.cache_by_default = 1
.
MYSQLND_QC_TTL_SWITCH
(string)
MYSQLND_QC_SERVER_ID_SWITCH
(string)
mysqlnd_qc_set_cache_condition() related
Example #2 Example mysqlnd_qc_set_cache_condition() usage
The function mysqlnd_qc_set_cache_condition() allows setting conditions for automatic caching of statements which don't begin with the SQL hints necessary to manually enable caching.
<?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");
?>
MYSQLND_QC_CONDITION_META_SCHEMA_PATTERN
(int)
Other
The plugin version number can be obtained using either
MYSQLND_QC_VERSION
, which is the string representation
of the numerical version number, or MYSQLND_QC_VERSION_ID
,
which is an integer such as 10000. Developers can calculate the version number
as follows.
Version (part) | Example |
---|---|
Major*10000 | 1*10000 = 10000 |
Minor*100 | 0*100 = 0 |
Patch | 0 = 0 |
MYSQLND_QC_VERSION_ID | 10000 |
MYSQLND_QC_VERSION
(string)
1.0.0-prototype.
MYSQLND_QC_VERSION_ID
(int)