mysqli_query()函數(shù)對數(shù)據(jù)庫執(zhí)行一次查詢
mysqli_query()函數(shù)接受表示查詢的字符串值作為參數(shù)之一，并在數(shù)據(jù)庫上執(zhí)行給定的查詢。
mysqli_query($con, query)
| 序號 | 參數(shù)及說明 |
|---|---|
| 1 | con(必需) 這是一個表示與MySQL Server的連接的對象。 |
| 2 | query(必需) 這是一個字符串值，表示要執(zhí)行的查詢。 |
| 3 | mode(可選) 這是表示結果模式的整數(shù)值。您可以將MYSQLI_USE_RESULT或MYSQLI_STORE_RESULT作為值傳遞給此參數(shù)。 |
失敗時返回 FALSE，通過mysqli_query() 成功執(zhí)行SELECT, SHOW, DESCRIBE或 EXPLAIN查詢會返回一個mysqli_result 對象，其他查詢則返回TRUE。
對于其他查詢此函數(shù)返回一個布爾值，如果操作/查詢成功，則為true，否則為false。
此函數(shù)最初是在PHP版本5中引入的，并且可以在所有更高版本中使用。
以下示例演示了mysqli_query()函數(shù)的用法（面向過程風格）-
<?php
$con = mysqli_connect("localhost", "root", "password", "mydb");
mysqli_query($con, "CREATE TABLE IF NOT EXISTS my_team(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
print("創(chuàng)建表 ..."."\n");
//將記錄插入到my_team表中
mysqli_query($con, "insert into my_team values(1, 'Shikhar', 'Dhawan', 'Delhi', 'India')");
mysqli_query($con, "insert into my_team values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
mysqli_query($con, "insert into my_team values(3, 'Kumara', 'Sangakkara', 'Matale', 'Srilanka')");
mysqli_query($con, "insert into my_team values(4, 'Virat', 'Kohli', 'Delhi', 'India')");
print("插入記錄 ..."."\n");
//關閉連接
mysqli_close($con);
?>輸出結果
創(chuàng)建表 ... 插入記錄 ...
如果您觀察數(shù)據(jù)庫中表的內(nèi)容，則可以看到插入的記錄，如下所示：
mysql> select * from my_team; +------+------------+------------+----------------+-------------+ | ID | First_Name | Last_Name | Place_Of_Birth | Country | +------+------------+------------+----------------+-------------+ | 1 | Shikhar | Dhawan | Delhi | India | | 2 | Jonathan | Trott | CapeTown | SouthAfrica | | 3 | Kumara | Sangakkara | Matale | Srilanka | | 4 | Virat | Kohli | Delhi | India | +------+------------+------------+----------------+-------------+ 4 rows in set (0.00 sec)
在面向?qū)ο蟮臉邮街?，此函?shù)的語法為$con->query();。以下是面向?qū)ο箫L格中此函數(shù)的示例；
<?php
$con = new mysqli("localhost", "root", "password", "mydb");
//將記錄插入到players表中
$con->query("CREATE TABLE IF NOT EXISTS players(First_Name VARCHAR(255), Last_Name VARCHAR(255), Country VARCHAR(255))");
$con->query("insert into players values('Shikhar', 'Dhawan', 'India')");
$con->query("insert into players values('Jonathan', 'Trott', 'SouthAfrica')");
print("創(chuàng)建數(shù)據(jù)......");
//關閉連接
$res = $con -> close();
?>輸出結果
創(chuàng)建數(shù)據(jù)......
如果您觀察數(shù)據(jù)庫中表的內(nèi)容，則可以看到插入的記錄，如下所示：
mysql> select * from players; +------------+-----------+-------------+ | First_Name | Last_Name | Country | +------------+-----------+-------------+ | Shikhar | Dhawan | India | | Jonathan | Trott | SouthAfrica | +------------+-----------+-------------+ 2 rows in set (0.00 sec)
以下示例打印INSERT和SELECT查詢的結果-
<?php
//建立連接
$con = mysqli_connect("localhost", "root", "password", "mydb");
mysqli_query($con, "CREATE TABLE IF NOT EXISTS my_team(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
print("創(chuàng)建表 ..."."\n");
//將記錄插入到my_team表中
$res = mysqli_query($con, "insert into my_team values(1, 'Shikhar', 'Dhawan', 'Delhi', 'India')");
print("插入查詢的結果: ".$res."\n");
$res = mysqli_query($con, "insert into my_team values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
print("插入查詢的結果: ".$res);
$res = mysqli_query($con, "SELECT * FROM my_team");
print("Result of the SELECT query: ");
print_r($res);
//關閉連接
mysqli_close($con);
?>輸出結果
創(chuàng)建表 ... 插入查詢的結果: 1 插入查詢的結果: 1Result of the SELECT query: mysqli_result Object ( [current_field] => 0 [field_count] => 5 [lengths] => [num_rows] => 2 [type] => 0 )
假設我們已經(jīng)在數(shù)據(jù)庫中創(chuàng)建了一個players表并填充了它，如下所示-
CREATE TABLE Players (Name VARCHAR(255), Age INT, Score INT);
insert into Players values('Dhavan', 33, 90),('Rohit', 28, 26),('Kohli', 25, 50);以下示例執(zhí)行針對數(shù)據(jù)庫的查詢：
<?php
//建立連接
$con = mysqli_connect("localhost", "root", "password", "mydb");
//執(zhí)行多個查詢
$query = "SELECT * FROM players";
//檢索記錄
$res = mysqli_query($con, $query, MYSQLI_USE_RESULT);
if ($res) {
while ($row = mysqli_fetch_row($res)) {
print("Name: ".$row[0]."\n");
print("Age: ".$row[1]."\n");
}
}
//關閉連接
mysqli_close($con);
?>輸出結果
Name: Dhavan Age: 33 Name: Rohit Age: 28 Name: Kohli Age: 25