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Full Discussion: Optimizing query
Special Forums UNIX and Linux Applications Optimizing query Post 302130200 by matrixmadhan on Friday 3rd of August 2007 01:50:55 PM
Old 08-03-2007
Quote:
Originally Posted by jim mcnamara
rowid is not an indexed column - it is a "pseudocolumn'. the in () subselect will read thru the entire select statement's result set each time. When I get back in a while I'll write something that is faster. You may need to add an index.
Does that mean its executing in this fashion.

rowid <1> - evaluate sub query
rowid <2> - evaluate sub query
.
.
.
rowid <n> - evaluate sub query

Last edited by reborg; 08-03-2007 at 03:29 PM.. Reason: touch post to fix quotes
 

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MYSQLI_AFFECTED_ROWS(3) 						 1						   MYSQLI_AFFECTED_ROWS(3)

mysqli::$affected_rows - Gets the number of affected rows in a previous MySQL operation

       Object oriented style

SYNOPSIS
int$mysqli->affected_rows () DESCRIPTION
Procedural style int mysqli_affected_rows (mysqli $link) Returns the number of rows affected by the last INSERT, UPDATE, REPLACE or DELETE query. For SELECT statements mysqli_affected_rows(3) works like mysqli_num_rows(3). PARAMETERS
o $ link -Procedural style only: A link identifier returned by mysqli_connect(3) or mysqli_init(3) RETURN VALUES
An integer greater than zero indicates the number of rows affected or retrieved. Zero indicates that no records were updated for an UPDATE statement, no rows matched the WHERE clause in the query or that no query has yet been executed. -1 indicates that the query returned an error. Note If the number of affected rows is greater than the maximum integer value( PHP_INT_MAX ), the number of affected rows will be returned as a string. EXAMPLES
Example #1 $mysqli->affected_rows example Object oriented style <?php $mysqli = new mysqli("localhost", "my_user", "my_password", "world"); /* check connection */ if (mysqli_connect_errno()) { printf("Connect failed: %s ", mysqli_connect_error()); exit(); } /* Insert rows */ $mysqli->query("CREATE TABLE Language SELECT * from CountryLanguage"); printf("Affected rows (INSERT): %d ", $mysqli->affected_rows); $mysqli->query("ALTER TABLE Language ADD Status int default 0"); /* update rows */ $mysqli->query("UPDATE Language SET Status=1 WHERE Percentage > 50"); printf("Affected rows (UPDATE): %d ", $mysqli->affected_rows); /* delete rows */ $mysqli->query("DELETE FROM Language WHERE Percentage < 50"); printf("Affected rows (DELETE): %d ", $mysqli->affected_rows); /* select all rows */ $result = $mysqli->query("SELECT CountryCode FROM Language"); printf("Affected rows (SELECT): %d ", $mysqli->affected_rows); $result->close(); /* Delete table Language */ $mysqli->query("DROP TABLE Language"); /* close connection */ $mysqli->close(); ?> Procedural style <?php $link = mysqli_connect("localhost", "my_user", "my_password", "world"); if (!$link) { printf("Can't connect to localhost. Error: %s ", mysqli_connect_error()); exit(); } /* Insert rows */ mysqli_query($link, "CREATE TABLE Language SELECT * from CountryLanguage"); printf("Affected rows (INSERT): %d ", mysqli_affected_rows($link)); mysqli_query($link, "ALTER TABLE Language ADD Status int default 0"); /* update rows */ mysqli_query($link, "UPDATE Language SET Status=1 WHERE Percentage > 50"); printf("Affected rows (UPDATE): %d ", mysqli_affected_rows($link)); /* delete rows */ mysqli_query($link, "DELETE FROM Language WHERE Percentage < 50"); printf("Affected rows (DELETE): %d ", mysqli_affected_rows($link)); /* select all rows */ $result = mysqli_query($link, "SELECT CountryCode FROM Language"); printf("Affected rows (SELECT): %d ", mysqli_affected_rows($link)); mysqli_free_result($result); /* Delete table Language */ mysqli_query($link, "DROP TABLE Language"); /* close connection */ mysqli_close($link); ?> The above examples will output: Affected rows (INSERT): 984 Affected rows (UPDATE): 168 Affected rows (DELETE): 815 Affected rows (SELECT): 169 SEE ALSO
mysqli_num_rows(3), mysqli_info(3). PHP Documentation Group MYSQLI_AFFECTED_ROWS(3)
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