在iPhone中通过sqlite从数据库检索数据

Question

I am developing an application in iphone to access the database through sqlite. I declared a method to retrieve the data from database. Whether the return type is an NSArray for this method? After the sqlite select statement what should we do to retrieve the data?

I mean after this query.

NSString *selectStmt=[NSString stringWithFormat:@"select * from %@" , tableName];
sqlite3_prepare_v2(db, [selectStmt UTF8STRING] , -1, &statement, NULL);

please help me out.

Answer 1

NSString *selectStmt=[NSString stringWithFormat:@"select * from %@", tableName];

if( sqlite3_prepare_v2(db, [selectStmt UTF8STRING] , -1,&statement, NULL) == SQLITE_OK ) {
while( sqlite3_step(statement) == SQLITE_ROW ) {

 } 
  }

Here in while you can get data from sqlite and add it to array !!!

Good luck !!!

Answer 2

const char *sqlStatement = "your query";

if(sqlite3_prepare_v2(database, sqlStatement, -1, &selectStmt, NULL) == SQLITE_OK) 
{
    // Loop through the results and add them to the feeds array
    while(sqlite3_step(selectStmt) == SQLITE_ROW) 
    {
        NSString *stringField = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectStmt, 1)];
        NSInteger intField = sqlite3_column_int(selectStmt, 0);
    }
}

sqlite3_finalize(selectStmt);
selectStmt = nil;

This way you need to read from the database. You can manage all those retrieved fields by declaring a Class. eg if retrieving fields from Login table you can have class as LoginClass with 2 Properties UserName,Password. Create instance of this class and store fields values retrieved from Db and add it to Array and use them any where Like that.

Hope this helps.

Answer 3

const char *sql = "select * from stocks";

sqlite3_stmt *output;

if(sqlite3_prepare_v2(dbase, sql, -1, &output, NULL)==SQLITE_OK)
{
[temp removeAllObjects];
[temp1 removeAllObjects];
while(sqlite3_step(output)==SQLITE_ROW)
{

    NSMutableString *str = [NSString stringWithUTF8String:(char  *)sqlite3_column_text(output, 0)];
    [temp1 addObject:str];
    str = [NSString stringWithUTF8String:(char *)sqlite3_column_text(output, 1)];
    [temp addObject:str];
}

}