从特定日期和显示消息的sql检索数据

Question

我想从特定日期的sql检索日期，并希望显示消息，如果数据不可用的特定日期。

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