PHP和MySQL如果表为空

Question

I have this section of cod:

how i can stop this section

for($i=0; $i<$n-1 ; $i++) {
    mysqli_query($con,"INSERT INTO text (ID, TXT) 
        VALUES ('$id', '$sir[$i]')");
            $id++;         
}

if table isn't empty ?

Answer 1

Do a

SELECT COUNT(*) AS cnt FROM text

and check how many entries you have. If cnt>0 place a break at the beginning of loop.

Answer 2

You need to add before the specific block:

// count the rows
$res = mysqli_query($con, "SELECT COUNT(ID) as numrows FROM text");
// fetch the result
$data=mysql_fetch_assoc($res);
// check if count = 0
if($data['numrows'] == 0) {
    // execute the codeblock
    for($i=0; $i<$n-1 ; $i++) {
        mysqli_query($con,"INSERT INTO text (ID, TXT) 
        VALUES ('$id', '$sir[$i]')");
            $id++;         
    }
}

Answer 3

How about insert if table is empty as below?

INSERT INTO my_table (colname)
SELECT 'foo'
WHERE NOT EXISTS (SELECT * FROM my_table)

Answer 4

Just a select a row and see what happens...

if (!($result = mysqli_query($con, "SELECT ID FROM text LIMIT 1")) || $result->num_rows < 1) {
    if($result) {
        $result->close();
    }
    for ($i = 0; $i < $n - 1; $i++) {
        mysqli_query($con, "INSERT INTO text (ID, TXT)
            VALUES ('$id', '$sir[$i]')");
        $id++;
    }
}