When should the WHERE clause be used in an INSERT statement in PHP?

The WHERE clause should not be used in an INSERT statement in PHP. The WHERE clause is used in SQL statements like SELECT, UPDATE, and DELETE to specify conditions for filtering records. In an INSERT statement, you are simply adding a new record to the database without any conditions. If you need to check for existing records before inserting, you should use a SELECT statement with a WHERE clause to determine if the record already exists. 

// Example of checking if a record exists before inserting
$check_query = "SELECT * FROM table_name WHERE column_name = 'value'";
$check_result = mysqli_query($connection, $check_query);

if(mysqli_num_rows($check_result) == 0) {
    // Insert statement
    $insert_query = "INSERT INTO table_name (column1, column2) VALUES ('value1', 'value2')";
    mysqli_query($connection, $insert_query);
} else {
    echo "Record already exists";
}

Keywords

WHERE clause INSERT statement PHP SQL database

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