sqlite3在iphone编程中准备插入查询

时间:2009-05-20 04:43:30

标签: iphone objective-c cocoa sqlite

(BOOL) addticket {
    NSString *event=@"max";
    NSString *venue=@"tvm";
    sqlite3 *database;
    databaseName = @"smbhDB.sql";
    sqlite3_stmt *addStatement ;
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,  NSUserDomainMask, YES);
    NSString *documentsDir = [documentPaths objectAtIndex:0];
    databasePath = [documentsDir stringByAppendingPathComponent:databaseName];
    if(addStatement == nil) {   
        const char *sql ="insert into tickets (venue, event,) Values (?,?)";

        if(sqlite3_prepare_v2(database, sql, -1, &addStatement, NULL) != SQLITE_OK)
            NSAssert1(0, @"444 Error while creating add  statement. '%s'", sqlite3_errmsg(database));
    }

    sqlite3_bind_text(addStatement, 1, [venue UTF8String], -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(addStatement, 2, [event UTF8String], -1, SQLITE_TRANSIENT);

    if(SQLITE_DONE != sqlite3_step(addStatement))
        NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database));

    sqlite3_reset(addStatement);
...

此代码无效。请有人帮我纠正。如果有人可以发布示例代码,请上传。

3 个答案:

答案 0 :(得分:3)

Dublicate? Why can't I execute this code?

您必须在执行语句

之前打开数据库

答案 1 :(得分:1)

考虑FMDB或Omni核心数据,如库。所有细节都隐藏在一个简单易用的抽象界面背后。

http://gusmueller.com/blog/archives/2008/03/fmdb_for_iphone.html

http://www.omnigroup.com/developer(OmniDataObjects)

祝你好运。

答案 2 :(得分:1)

我不是百分百肯定,因为没有提供错误详细信息,但看起来addStatement未初始化。 Objective-C是否在堆栈上分配时将所有指针初始化为0?我知道在Linux中无法正常工作。

也许试试这个:sqlite3_stmt *addStatement = nil;

我不得不怀疑,你为什么要查看addStatement == nil?没有理由检查它,因为你必须在每种情况下初始化它。

简而言之,就像这样重写:

(BOOL) addticket {
    NSString *event=@"max";
    NSString *venue=@"tvm";
    sqlite3 *database;
    databaseName = @"smbhDB.sql";
    sqlite3_stmt *addStatement ;
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,  NSUserDomainMask, YES);
    NSString *documentsDir = [documentPaths objectAtIndex:0];
    const char *sql ="insert into tickets (venue, event,) Values (?,?)";

    databasePath = [documentsDir stringByAppendingPathComponent:databaseName];

    /* this is no longer conditional code */
    if(sqlite3_prepare_v2(database, sql, -1, &addStatement, NULL) != SQLITE_OK)
        NSAssert1(0, @"444 Error while creating add  statement. '%s'", sqlite3_errmsg(database));

    sqlite3_bind_text(addStatement, 1, [venue UTF8String], -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(addStatement, 2, [event UTF8String], -1, SQLITE_TRANSIENT);

    if(SQLITE_DONE != sqlite3_step(addStatement))
        NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database));

    sqlite3_reset(addStatement);
...