我需要检查值是否已经存在于表中,如果不存在则插入它,否则我需要显示异常警报
现在我只插入数据而不检查
if(isset($_POST['new_ok'])){$result = mysql_query("INSERT INTO db1 (name) VALUES('".$name."')",$db);}
我试着那样做
if(isset($_POST['new_ok'])){if(mysql_num_rows(mysql_query("SELECT name FROM db1 WHERE name= '$name'");) != 0){$result = mysql_query("INSERT INTO db1 (name) VALUES('".$name."')",$db);}else{echo "wrong";}}
但是mysql_num_rows 总是
返回1
最佳答案
试试这个例子
$sq="SELECT * FROM db1 WHERE username='$name'";
$rsult=mysql_query($sq); $count=mysql_num_rows ($rsult);
if($count==1){echo "username already in use"; }
else
{//update statement here}
关于php - Mysql插入数据如果不存在否则显示警告,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/28646984/