Question

- （void）readProductsFromDatabase { //设置数据库对象 sqlite3 *数据库;

// Init the animals Array
products = [[NSMutableArray alloc] init];

// Open the database from the users filessytem
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) {
    NSLog(@"db opened");
    // Setup the SQL Statement and compile it for faster access
    const char *sqlStatement = "SELECT DISTINCT productname FROM iphone ";
            sqlite3_stmt *compiledStatement;
    if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) 
    {
        // Loop through the results and add them to the feeds array
        while(sqlite3_step(compiledStatement) == SQLITE_ROW)
        {
            NSLog(@"inside sqlite3 prepare");
            // Read the data from the result row
            NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];


                    }
    }
    // Release the compiled statement from memory
    sqlite3_finalize(compiledStatement);

}
sqlite3_close(database);

}

我的问题是

const char * sqlStatement =“SELECT DISTINCT productname FROM iphone”;

此行未执行，我使用的是sqlite3，提前谢谢，

Answer 1

问题在于此步骤 NSString * aName = [NSString stringWithUTF8String：（char *）sqlite3_column_text（compiledStatement，2）];

而不是2使用0

从xcode无法为sqlite执行DISTINCT关键字

1 个答案: