sqlite, select query doesn't work - iphone

Question

- (UserInfo*)getCurrentUserInfo:(NSString*)userName
{
UserInfo *userInfo = [[UserInfo alloc]init];
sqlite3 *database;
sqlite3_stmt *selectstmt;
NSLog(#"userName:%#",userName);
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) {
NSString *sqlString = [NSString stringWithFormat:#"SELECT USER_LEVEL FROM USER_INFO WHERE USER_NAME = '%#'" , userName];
NSLog(#"getCurrentUserInfo:%#",sqlString);
const char *SqlCommand = [sqlString UTF8String];
if (sqlite3_prepare_v2(database, SqlCommand, -1, &selectstmt, NULL) == SQLITE_OK) {
NSLog(#"success!");
while (sqlite3_step(selectstmt) == SQLITE_ROW) {
NSString *userInfoStr = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 0)];
NSLog(#"select result:%#",userInfoStr);
}
}
sqlite3_finalize(selectstmt);
}
sqlite3_close (database);
return userInfo;
}
the following is my log output:
2012-03-06 17:50:11.556 MagicWords[508:f803] userName:Tan
2012-03-06 17:50:11.557 MagicWords[508:f803] getCurrentUserInfo:SELECT USER_LEVEL FROM USER_INFO WHERE USER_NAME = 'Tan'
It doesn't print "success",so sqlite3_prepare_v2 don't return yes.but my database is ok:
I can't find the problem?

Answer 1

Add sqlite error message . It will give an insight of what is going on inside. If all about your database is correct ,check the table name.
UserInfo *userInfo = [[UserInfo alloc]init];
sqlite3 *database;
sqlite3_stmt *selectstmt;
NSLog(#"userName:%#",userName);
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) {
NSString *sqlString = [NSString stringWithFormat:#"SELECT USER_LEVEL FROM USER_INFO WHERE USER_NAME = '%#'" , userName];
NSLog(#"getCurrentUserInfo:%#",sqlString);
const char *SqlCommand = [sqlString UTF8String];
if (sqlite3_prepare_v2(database, SqlCommand, -1, &selectstmt, NULL) == SQLITE_OK) {
NSLog(#"success!");
while (sqlite3_step(selectstmt) == SQLITE_ROW) {
NSString *userInfoStr = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 0)];
NSLog(#"select result:%#",userInfoStr);
}
}
//Add the error message here.
else
{
NSLog(#"%s",sqlite3_errmsg(database));
}
///////
sqlite3_finalize(selectstmt);
}
sqlite3_close (database);
return userInfo;

Answer 2

Remove the quotes inside ' ' and Use Semicolon at the end of the sqlString.
NSString *sqlString = [NSString stringWithFormat:#"SELECT USER_LEVEL FROM USER_INFO WHERE USER_NAME = %#;" , userName];

Answer 3

try this when you are converting sqlString to char
const char *SqlCommand = (char *)[sqlString
cStringUsingEncoding:NSUTF8StringEncoding];