php - 从特定日期的 sql 中检索数据并显示消息

Question

我想从特定日期的 sql 中检索日期，如果特定日期的数据不可用，我想显示消息。

Answer 1

$result = mysql_query("SELECT * FROM yourTable WHERE date = 'dateYouWantToCheck'");
$num_rows = mysql_num_rows($result); //count number of rows returned

if($num_rows > 0)
{
   //Show details here
}
else
{
   echo "No match found";
}

Answer 2

伪代码

SELECT CASE WHEN LENGTH(X.DATA) > 0 THEN X.DATA ELSE 'No Data Found' END

FROM 

(SELECT DATA FROM <TABLE NAME> WHERE DATE = <SOME DATE> )X