Php code for moving a pointer to the initial position of a dataset [mysql_data_seek]

Copy codeThe Code is as follows: <?
// Start snipit 1
$ SQL = "SELECT * from <table> ";
$ Result = mysql_query ($ SQL );
While ($ row = mysql_fetch_assoc ($ result )){
// Do stuff with $ row
}
Mysql_data_seek ($ result, 0); // The Key is here
While ($ row = mysql_fetch_assoc ($ result )){
// Do other stuff with $ row
}
?>

Definition and usage

The mysql_data_seek () function moves the internal result pointer.

Syntax

Mysql_data_seek (data, row) parameter description
Data is required. Returns a result set of the resource type. This result set is obtained from the call of mysql_query.
Row is required. The number of rows of the new result set pointer to be set. 0 indicates the first record.

Description

Mysql_data_seek () moves the row pointer inside the MySQL result specified by the data parameter to the specified row number.
Call mysql_fetch_row () to return the row.
Row starts from 0. The value range of row is from 0 to mysql_num_rows-1.
However, if the result set is empty (mysql_num_rows () = 0), moving the pointer to 0 fails and an E_WARNING error is returned. mysql_data_seek () returns false.

Return Value

If the call succeeds, true is returned. If the call fails, false is returned.

Tips and comments

Note: mysql_data_seek () can only be used with mysql_query (), but cannot be used with mysql_unbuffered_query ().

ExampleCopy codeThe Code is as follows: <? Php
$ Con= mysql_connect ("localhost", "hello", "321 ");
If (! $ Con)
{
Die ('could not connect: '. mysql_error ());
}
$ Db_selected = mysql_select_db ("test_db", $ con );
$ SQL = "SELECT * from Person ";
$ Result = mysql_query ($ SQL, $ con );
Print_r (mysql_fetch_row ($ result ));
Mysql_data_seek ($ result, 3 );
Print_r (mysql_fetch_row ($ result ));
Mysql_close ($ con );
?>

Output:Copy codeThe Code is as follows: Array
(
[0] => Adams
[1] => John
[2] => London
)

Array
(
[0] => Carter
[1] => Thomas
[2] => Beijing
)