mysqli_get_warnings()函數(shù)返回上一次執(zhí)行的查詢所產(chǎn)生的錯(cuò)誤。
如果您的最后一個(gè)MySQLi函數(shù)調(diào)用執(zhí)行MySQL查詢，并且它生成任何錯(cuò)誤。mysqli_get_warnings()函數(shù)以數(shù)組的形式返回上一次執(zhí)行的查詢所生成的錯(cuò)誤。
mysqli_get_warnings($con)
| 序號(hào) | 參數(shù)及說明 |
|---|---|
| 1 | con(必需) 這是一個(gè)表示與MySQL Server的連接的對(duì)象。 |
PHP mysqli_get_warnings()函數(shù)返回一個(gè)數(shù)組，其中包含上一次查詢執(zhí)行期間生成的警告。
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。
假設(shè)我們創(chuàng)建了一個(gè)名為Emp的表，如下所示：
CREATE TABLE EMP( ID TINYINT, First_Name VARCHAR(50) Not NULL, Last_Name VARCHAR(10) Not NULL, Date_Of_Birth date, Salary Int(255) );
以下示例演示了mysqli_get_warnings()函數(shù)的用法（面向過程風(fēng)格）-
<?php
//建立連接
$con = mysqli_connect("localhost", "root", "password", "mydb");
//插入記錄到 employee 表中
$sql = "INSERT IGNORE into emp values(1, 'Sanjay', NULL, DATE('1981-12-05'), 2566)";
mysqli_query($con, $sql);
//Warnings
$warnings = mysqli_get_warnings($con);
print("Warning(s): "."\n");
print_r($warnings);
$sql = "INSERT IGNORE into emp values (15, 'Swetha', 'Yellapragada', DATE('1990-11-25'), 9986), (15, NULL, 'Prayaga', DATE('1990-11-25'), 9986)";
mysqli_query($con, $sql);
//Warnings
$warnings = mysqli_get_warnings($con);
print("\n"."Warning(s): ");
print_r($warnings);
//關(guān)閉連接
mysqli_close($con);
?>輸出結(jié)果
Warning(s): mysqli_warning Object ( [message] => Column 'Last_Name' cannot be null [sqlstate] => HY000 [errno] => 1048 ) Warning(s): mysqli_warning Object ( [message] => Data truncated for column 'Last_Name' at row 1 [sqlstate] => HY000 [errno] => 1265 )
以下是函數(shù)mysqli_get_warnings()的另一個(gè)示例-
<?php
//建立連接
$con = mysqli_connect("localhost", "root", "password", "mydb");
//刪除未知表
mysqli_query($con, "drop table if exists WrongTable");
print("\n"."Warning(s): "."\n");
print_r(mysqli_get_warnings($con));
//關(guān)閉連接
mysqli_close($con);
?>輸出結(jié)果
Warning(s): mysqli_warning Object ( [message] => Unknown table 'mydb.wrongtable' [sqlstate] => HY000 [errno] => 1051 )
您也可以使用mysqli_warning類的next()函數(shù)一個(gè)接一個(gè)地檢索警告，如下所示：
<?php
//建立連接
$con = new mysqli("localhost", "root", "password", "mydb");
//插入記錄到 employee 表中
$con -> query("INSERT IGNORE into emp values(105, NULL, 'Yellapragada', DATE('1981-12-05'), 2566)");
if($con->warning_count){
$w = mysqli_get_warnings($con);
do {
echo "Warning: $w->errno: $w->message\n";
} while ($w->next());
}
//關(guān)閉連接
$con -> close();
?>輸出結(jié)果
Warning: 1048: Column 'First_Name' cannot be null Warning: 1265: Data truncated for column 'Last_Name' at row 1
返回上一次執(zhí)行的查詢所產(chǎn)生的錯(cuò)誤
<?php
$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "mydb";
$conn = new mysqli($servername, $username, $password, $dbname);
if (!$conn->real_connect($servername, $username, $password, $dbname)) {
die('Connect Error (' . mysqli_connect_errno() . ') '. mysqli_connect_error());
}
print("數(shù)據(jù)庫已連接" ."\n");
mysqli_query($conn, "CREATE TABLE sample (ID INT, Name VARCHAR(20))");
$query = "INSERT IGNORE INTO sample (id,name) VALUES(
1,'Rajesh Ramayan Kootrapally')";
mysqli_query($conn, $query);
$count = mysqli_warning_count($conn);
print("No.Of warnings in the query:".$count."\n");
if ($count) {
$warnings = mysqli_get_warnings($conn);
print_r($warnings);
}
mysqli_close($conn);
?>輸出結(jié)果
數(shù)據(jù)庫已連接 No.Of warnings in the query:1 mysqli_warning Object ( [message] => Data truncated for column 'Name' at row 1 [sqlstate] => HY000 [errno] => 1265 )