(PHP 5)
mysqli::store_result -- mysqli_store_result — Transfers a result set from the last query
面向对象风格
过程化风格
Transfers the result set from the last query on the database connection
represented by the link parameter to be used with
the mysqli_data_seek() function.
Returns a buffered result object or FALSE if an error occurred.
Note:
mysqli_store_result() returns
FALSEin case the query didn't return a result set (if the query was, for example an INSERT statement). This function also returnsFALSEif the reading of the result set failed. You can check if you have got an error by checking if mysqli_error() doesn't return an empty string, if mysqli_errno() returns a non zero value, or if mysqli_field_count() returns a non zero value. Also possible reason for this function returningFALSEafter successful call to mysqli_query() can be too large result set (memory for it cannot be allocated). If mysqli_field_count() returns a non-zero value, the statement should have produced a non-empty result set.
Note:
Although it is always good practice to free the memory used by the result of a query using the mysqli_free_result() function, when transferring large result sets using the mysqli_store_result() this becomes particularly important.
See mysqli_multi_query().
mitchind (2010-02-04 20:28:26)
After reading through original notes and example above as well as wading through the documentation, I finally got a loop to work with two stored procedures.
Using the results of the first one as a parameter for the second one. Easier to do this way than a huge modified sequence of Inner Join queries.
Hope this helps others...
<?php
// Connect to server and database
$mysqli = new mysqli("$dbServer", "$dbUser", "$dbPass", "$dbName");
// Open First Stored Procedure using MYSQLI_STORE_RESULT to retain for looping
$resultPicks = $mysqli->query("CALL $proc ($searchDate, $maxRSI, $incRSI, $minMACD, $minVol, $minTrades, $minClose, $maxClose)", MYSQLI_STORE_RESULT);
// process one row at a time from first SP
while($picksRow = $resultPicks->fetch_array(MYSQLI_ASSOC)) {
// Get Parameter for next SP
$symbol = $picksRow['Symbol'];
// Free stored results
clearStoredResults($mysqli);
// Execute second SP using value from first as a parameter (MYSQLI_USE_RESULT and free result right away)
$resultData = $mysqli->query("CALL prcGetLastMACDDatesBelowZero('$symbol', $searchDate)", MYSQLI_USE_RESULT);
$dataRow = $resultData->fetch_array(MYSQLI_ASSOC);
// Dump result from both related queries
echo "<p>$symbol ... Num Dates: " . $dataRow['NumDates'];
// Free results from second SP
$resultData->free();
}
// Free results from first SP
$resultPicks->free();
// close connections
$mysqli->close();
#------------------------------------------
function clearStoredResults($mysqli_link){
#------------------------------------------
while($mysqli_link->next_result()){
if($l_result = $mysqli_link->store_result()){
$l_result->free();
}
}
}
?>
Warner (2009-07-21 02:45:41)
It also seems, that executing a SET statement in multi_query() returns an extra recordset too, which one would not expect.
lau at goldenweb dot com dot au (2007-04-13 01:29:02)
Beware when using stored procedures:
If you connect to the database and then call dbproc A followed by a call to db proc B and then close the connection to the db, the second procedure call will not work.
It looks like there is a bug in MYSQL or mysqli that returns an extra recordset than you would expect. It then doesn't let you call another stored procedure until you finish processing all the recordsets from the first stored procedure call.
The solution is to simply loop through the additional recordsets between calls to db procs. Here is a function that I call between db proc calls:
<?php
#--------------------------------
function ClearRecordsets($p_Result){
#--------------------------------
$p_Result->free();
while($this->Mysqli->next_result()){
if($l_result = $this->Mysqli->store_result()){
$l_result->free();
}
}
}
?>