SQLite3 - 不按顺序调用的库例程

Question

当为SQLite3 db-selecct查询运行以下准备语句时,我得到一个SQLLite错误21" 库程序不按顺序调用 ":

sqlite3             *lDb;
sqlite3_stmt           *lStmt;
NSNumberFormatter     *lNbrFmt = [[[NSNumberFormatter alloc] init] autorelease];

// Define SQL statement 
NSString *lSql = @"SELECT section, language, title, description"
@"                        selector-x-pos, selector-y-pos, gps-x-pos, gps-y-pos"
@"                   FROM sections"
@"               ORDER BY section ASC";

lSqlResult = sqlite3_prepare_v2(lDb, [lSql UTF8String], -1, &lStmt, NULL);
NSLog(@"%@", [NSString stringWithUTF8String:sqlite3_errmsg(lDb)]);

我究竟做错了什么？

Answer 1

Uopon进一步调查我发现了我的错误.我应该在运行prep语句之前先打开db.

代码应该如下所示:

sqlite3             *lDb;
sqlite3_stmt           *lStmt;
NSNumberFormatter     *lNbrFmt = [[[NSNumberFormatter alloc] init] autorelease];

// Define SQL statement 
NSString *lSql = @"SELECT section, language, title, description"
@"                        selector-x-pos, selector-y-pos, gps-x-pos, gps-y-pos"
@"                   FROM sections"
@"               ORDER BY section ASC";

if(sqlite3_open([[fileMethods databasePath] UTF8String], &lDb) == SQLITE_OK) {
    lSqlResult = sqlite3_prepare_v2(lDb, [lSql UTF8String], -1, &lStmt, NULL);
    NSLog(@"%@", [NSString stringWithUTF8String:sqlite3_errmsg(lDb)]);
...