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Index › Programming Questions & Help › Syntax Questions › MySQL String Array

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MySQL String Array (Read 760 times)

brendan

MySQL String Array
Mar 14^th, 2007, 3:54pm

Hello all,

I've created a class using the MySQL library. My goal is to query a table from my database and output the result as a list of strings. So far I can get it to output the list of database entries in my class method getData(); but when I try to return this list of data I only get the last entry in the db. How do I fix this - create a String Array?

Quote:

class sql {
String user = "-user-";
String pass = "-pass-";
String database = "-db-";
String table = "-table-";
String host = "localhost";

String question;

// Constructor
sql(PApplet _p)
{
msql = new MySQL( host, database, user, pass, _p);

if ( !msql.connect() )

println("connection failed");

}

String getData() {
msql.query( "SELECT * FROM " + table );
while (msql.next())
{
String q = msql.getString("question");
question = q;
println(q); // Ouputs list of strings here OK!, But...
}
return question; // Only last string value is output here.... *** OUTPUT "String Array" here ? ***
}

}

Much appreciated!

Brendan

JohnG Ex Member	Re: MySQL String Array Reply #1 - Mar 14^th, 2007, 4:16pm You're only getting a single string, since that's what you're returning. If you want to return an array, you need to put the data into an array... You only need to change 3 lines: Code: // String question; String[] question; ... // String getData() { String[] getData(){ ... // question = q; question = append(question,q);

brendan

Re: MySQL String Array
Reply #2 - Mar 14^th, 2007, 4:57pm

Thanks for the reply John. I now get a NullPointerException error at "question = append(question,q);". Here's the new code:

Quote:

class sql {
String user = "-user-";
String pass = "-pass-";
String database = "-db-";
String table = "-table-";
String host = "localhost";
String[] question;

// CONTRUCTOR
sql(PApplet _p)
{
msql = new MySQL( host, database, user, pass, _p);

if ( !msql.connect() )

println("connection failed");

}

String[] getData() {

msql.query( "SELECT * FROM " + table );

while (msql.next())
{
String q = msql.getString("question");
question = append(question,q);
println(q);
}
return question;
}
}

JohnG Ex Member	Re: MySQL String Array Reply #3 - Mar 14^th, 2007, 5:27pm Ah yes, sorry, you need to add "question=new String[0];" into your constructor I think.

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