Question

I’m writing a quiz app using phonegap & jquery. I have a number of categories of question from which the user can select (via checkboxes), and want to build a database query to pull back the questions from the relevant categories based on their selection. The code below gives the gist of what I’m trying to achieve, but I cannot pass queryString into the executeSql() method. Is there a straightforward way of doing this that I’m missing? Thanks, Nick

function queryDB4(tx){
var queryString = "SELECT * FROM SBA_TABLE WHERE (";

if (toggle_cardiology == 1)
{
    queryString += "cat_cardiology = 1 AND";
}
else if (toggle_respiratory == 1)
{
    queryString += "cat_respiratory = 1"
}
// repeat for other categories

queryString += ") LIMIT 10;";
//alert(queryString);

tx.executeSql(queryString, [], querySuccess3, errorCB);

}

Answer 1

I think the problem is that your query string is invalid. Here’s one example string that your code could produce:

SELECT * FROM SBA_TABLE WHERE (cat_cardiology = 1 AND) LIMIT 10;

There are a number of problems:

• Append 1=1 (or any other statement that is always true) to handle the trailing AND.
• Omit the else clause to allow combinations of checkboxes, not just the first one that is checked.
• You need a space after AND to avoid producing ANDcat_respiratory.

Putting it together:

if (toggle_cardiology == 1)
{
    queryString += "cat_cardiology = 1 AND ";
}

if (toggle_respiratory == 1)
{
    queryString += "cat_respiratory = 1 AND ";
}

queryString += "1 = 1) LIMIT 10";