解析错误：语法错误，意外T_LNUMBER [重复]

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i have this error: "Parse error: syntax error, unexpected T_LNUMBER in line 14 " i would like to calculate difference between two dates

function datedifference()
{
   $res=dbconnect()->exec("SELECT DATEDIFF("2017-06-25", "2017-06-15");");

   echo $res;
}

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The problem is that your string syntax is wrong, you have not escaped the " quotes inside the string, you can either use ' single-quote or escape the double quote:

Single-quote:

$res = dbconnect()->exec("SELECT DATEDIFF('2017-06-25', '2017-06-15');");

Escaped double quote:

$res = dbconnect()->exec("SELECT DATEDIFF(\"2017-06-25\", \"2017-06-15\");");