PHP：使用IF语句生成SQL difficulites

Question

I'm having a problem with using IF statements to 'choose' some MySQL code to run. Here's my code:

if ($numRows == 0 && count($terms) == 3) {
    $query2 .= " AND ( i.ING = '" . join("' OR i.ING = '", $terms) . "')". $queryType ." GROUP BY r.recipeID
    HAVING COUNT(DISTINCT i.ING ) = 2)";
    $termCount = 2;

}

if ($numRows == 0 && $termCount == 2) {
    $query2 .= " AND ( i.ING = '" . join("' OR i.ING = '", $terms) . "')". $queryType ." GROUP BY r.recipeID
HAVING COUNT(DISTINCT i.ING ) = 1)";

This outputs:

    AND ( i.ING = 'wonton wrappers' OR i.ING = 'grape jelly' OR i.ING = 'lard') GROUP BY r.recipeID HAVING COUNT(DISTINCT i.ING ) = 2) 
AND ( i.ING = 'wonton wrappers' OR i.ING = 'grape jelly' OR i.ING = 'lard') GROUP BY r.recipeID HAVING COUNT(DISTINCT i.ING ) = 1)

However, i'm only wanting the 2nd line to be part of the query i'm going to use; but because the 1st if statement is always true aswell, it outputs that line too.

So the result I'd like to have based on the two statements is:

AND ( i.ING = 'wonton wrappers' OR i.ING = 'grape jelly' OR i.ING = 'lard') GROUP BY r.recipeID HAVING COUNT(DISTINCT i.ING ) = 1)

It might be a case of i've been looking at it too long, and can't notice if it's some simplest thing i'm overlooking.

Any ideas?

Thank you.

Answer 1

Assuming that this is the only code effected, I think your best bet is to simply replace if ($numRows == 0 && $termCount == 2) with elseif ($numRows == 0 && $termCount == 2) . (Basically, make it an else if clause to exclude the possibility of dupes)

Answer 2

I'd suggest splitting the logic like this:

if ($numRows == 0) {
  $query2 .= " AND ( i.ING = '" . join("' OR i.ING = '", $terms) . "')$queryType GROUP BY r.recipeID";

  $query2 .= " HAVING COUNT(DISTINCT i.ING) = " . (count($terms) == 3 ? 2 : 1);
}

Taking advantage of the fact your branches are basically the same.

Answer 3

In your first IF statement; if it is TRUE (and you enter that statement) you are setting $termCount to 2. The second IF statement depends on $termCount == 2. So right now if $numRows is 0 then both statements will always be true. Find a different way to trigger the second IF statement; or simply remove $termCount = 2 from the first IF statement

Answer 4

使用If else代替并形成您的语句，以便查询仅在逻辑上应该分配给$ query。