Mysqli Object-oriented practice--multi_query

you can implement multiple SQL statements using Multi_query, and each SQL statement is separated by semicolons. It is important to note that:

In a semicolon-delimited SQL statement, this SQL statement and subsequent SQL statements will not execute as long as one of the SQL statements fails to execute.

The return value of Multi_query () is false only if the first SQL statement fails to execute. If the first SQL statement executes successfully, it will return true.

<?php    $mysqli = new mysqli ();    $mysqli->connect ("localhost", "root", "root", "test");    if ($mysqli->connect_errno) {die        ($mysqli->connect_error);    }    $mysqli->set_charset ("UTF8");    $sql = "";    $sql. = "TRUNCATE table mysqli;"; The first SQL statement    $sql. = "INSERT into mysqli (ID, name) VALUES (null, ' AAAA '), (null, ' bbbb ');"; /second SQL statement    $sql. = "Update table mysqli where uid = 1;"; /Third SQL statement, because there is no UID field, so there is an error    $sql. = "INSERT into mysqli (ID, name) VALUES (null, ' CCCC ');";    $res = $mysqli->multi_query ($sql);    Var_dump ($res);? >

To view the database:

Mysql> SELECT * FROM mysqli;+----+------+| ID | Name |+----+------+|  1 | AAAA | |  2 | BBBB |+----+------+2 rows in Set (0.00 sec)

You can see that the third SQL statement failed to execute, and the fourth SQL statement that inserted the data did not execute

multi_query Executing multiple select query statements

For multiple SELECT statements, there will be multiple result sets returned, so you need to "switch result sets",

You can use Mysqli_result Mysqli::use_result and Mysqli_result Mysqli::store_result () to get the result set that the pointer points to in the results of the multi_query. Traverse multiple result sets by moving the internal pointer.

You can use bool Mysqli::more_result () to detect if there is a result set, and if so, you can point the internal pointer to the next result set through bool Mysqli::next_result ().

Method One: Use Mysqli_result mysqli::use_result ()

<?php    $mysqli = new mysqli ();    $mysqli->connect ("localhost", "root", "root", "test");    if ($mysqli->connect_errno) {die        ($mysqli->connect_error);    }    $mysqli->set_charset ("UTF8");    $sql = "";    $sql. = "SELECT * from mysqli;";    $sql. = "SELECT * from User;";    $res = $mysqli->multi_query ($sql);    if ($res) {        do{            if ($mysqli _result = $mysqli->use_result ()) {                Print_r ($mysqli _result->fetch_all (MYSQLI_ASSOC));            }        } while ($mysqli->more_results () && $mysqli->next_result ());    } else {        echo "error". $mysqli->errno. ":". $mysqli->error;    }? >

　　

Method Two: Mysqli_result Mysqli::store_result ()

<?php    $mysqli = new mysqli ();    $mysqli->connect ("localhost", "root", "root", "test");    if ($mysqli->connect_errno) {die        ($mysqli->connect_error);    }    $mysqli->set_charset ("UTF8");    $sql = "";    $sql. = "SELECT * from mysqli;";    $sql. = "SELECT * from User;";    $res = $mysqli->multi_query ($sql);    if ($res) {        do{            if ($mysqli _result = $mysqli->store_result ()) {                Print_r ($mysqli _result->fetch_ All (MYSQLI_ASSOC));            }        } while ($mysqli->more_results () && $mysqli->next_result ());    } else {        echo "error". $mysqli->errno. ":". $mysqli->error;    }? >

　　

Mysqli Object-oriented practice--multi_query