SQLite Exception no such column when trying to select

Question

I have the following DB helper class:

public int studentExists(String studid) {
    Cursor dataCount = mDb.rawQuery(\"select count(*) from usertable where \"         


        

Answer 1

You need to quote 'pb3874' (single quotes) if you are including it in the SQL string.

Answer 2

for STRING you should place that in between '' ('sasas')

select * from bio where email = 'sasas'

Answer 3

Error was in trigger being fired on database update

Answer 4

What's happening here is that SQLite thinks that 'pb3874' is actually a column name, rather than a string/text literal.

To specify that it's a text literal, you'll want to ensure your text value is wrapped in the appropriate single quotes:

To prevent SQL injection attacks, whenever you're taking input from the user, use a parameterized query:

("select count(*) from usertable where " + KEY_STUDID + "=?", studid);

Without parameterization (very much discouraged when taking user input):

("select count(*) from usertable where " + KEY_STUDID + "='" + studid + "'", null);  

The reason your numeric values didn't produce this: SQLite converted those numeric literals for you.

Answer 5

I think you got the answer to what's wrong from Antlersoft or p.campbell, to format the query correctly, I would suggest, you do it like this :

mDb.rawQuery("select count(*) from usertable where " + KEY_STUDID + "=?", studid);

That should (1) solve your problem and (2) protect you from SQL injections

Also, I am not sure that

dataCount.getInt(0);

is the best thing to do... you should probably use getColumnIndex to make sure you are getting the right data...