not getting inside while loop when selecting a single row from sqlite - iphone

Question

I have a problem with sqlite, when i select a single row from table and then check sqlite3_step(statement) == SQLITE_ROW both values are different and not getting inside while statement.
This is the code:
if (sqlite3_prepare_v2(db, query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
//NSLog(#"working777.............%d",sqlite3_step(statement));
while (sqlite3_step(statement) == SQLITE_ROW)
{
NSLog(#"working888.............%d",SQLITE_ROW);
NSString *addressField = [[NSString alloc] initWithUTF8String: (const char *) sqlite3_column_text(statement, 0)];
NSString *phoneField = [[NSString alloc] initWithUTF8String:(const char *)sqlite3_column_text(statement, 1)];
NSLog(#"............statement...........addressField %#, phoneField %#",addressField,phoneField);
}
sqlite3_finalize(statement);
}
sqlite3_close(db);
}

Answer 1

The proper way to create such a query would be like this:
NSString *querySQL = #"SELECT * FROM Major_Events WHERE temple_id = ?";
Then prepare the statement. I assume query_stmt is the char * value from querySQL.
Once the statement is prepared you then need to bind the value.
sqlite3_bind_int(statement, 1, temp_id); // bind is 1-based
Of course temp_id needs to be an int value and not a string. There are various sqlite3_bind_xxx statements for different data types. Use the appropriate one.
Once all of the query parameters are bound, you can execute the query using sqlite3_step.
The nice thing about this approach over string formats is that strings get properly escape and put in quotes for you. It's much harder to mess up and it makes your queries much safer against SQL injection attacks.

Answer 2

For many records:-
if (sqlite3_open([[self getDBPath] UTF8String], &database) == SQLITE_OK) {
const char *sql = "select * from Place";
sqlite3_stmt *selectstmt;
if(sqlite3_prepare_v2(database, sql, -1, &selectstmt, NULL) == SQLITE_OK) {
while(sqlite3_step(selectstmt) == SQLITE_ROW) {
}
sqlite3_finalize(selectstmt);
sqlite3_close(database);
}
}
else
{
sqlite3_close(database);
}
If you want a single record then change while to if
if(sqlite3_step(selectstmt) == SQLITE_ROW) {
rest everything will be same
I hope it helps and if your while loop is not getting executed then it means there is some problem with your query.You need to check that also.