Question

我正在尝试从我的数据库“下面提到的代码”中删除一行，但它从不删除该行，并且似乎也从未调用过准备语句。

我可以插入并更新确定但是对于我的生活无法弄清楚这一点..

条形码是从可编辑的tableview传递给方法的字符串变量。

当我记录deletSQL字符串时，我可以看到正确的值但实际上从未删除记录。

有关详细信息，数据库中的条形码是主键。

数据库路径也都正确，并且调用正确的db文件。

只是删除功能无效...

-(void)delete:(NSString *)barcode{

const char *dbpath = [databasePath3 UTF8String];
if (sqlite3_open(dbpath, &database3) == SQLITE_OK)
{

    NSLog(@"Opened OK");

NSString *deleteSQL = [NSString stringWithFormat: @"delete from assets where assetBarcode=\"%@\'",barcode];
NSLog(@"%@",deleteSQL);
const char *sql = [deleteSQL UTF8String];

if(sqlite3_prepare_v2(database3, sql, 1, &deleteStatement, NULL) == SQLITE_OK)
{

    NSLog(@"SQL OK?");

    if (sqlite3_step(deleteStatement) == SQLITE_ROW)
    {

        sqlite3_bind_text(deleteStatement, 1, [barcode UTF8String], -1, SQLITE_TRANSIENT);

    }

}

else{

    NSLog(@"WHAAAATTTTT");
}

}

sqlite3_step(deleteStatement);
sqlite3_reset(deleteStatement);
sqlite3_close(database3);

}

Answer 1

数据库中的条形码列似乎是varchar

类型

试试这个

- （void）delete：（NSString *）条形码
{{/ p>

if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) 
{
    if(deleteStatement == nil)
    {
        const char *sql = "DELETE FROM assets WHERE assetBarcode = ?";
        if(sqlite3_prepare_v2(database, sql, -1, & deleteStatement, NULL) != SQLITE_OK)
            NSAssert1(0, @"Error while creating delete statement. '%s'", sqlite3_errmsg(database));
    }

    sqlite3_bind_text(deleteStatement, 1, [barcode UTF8String], -1, SQLITE_TRANSIENT);

    if(SQLITE_DONE != sqlite3_step(deleteStatement))
        NSAssert1(0, @"Error while deleting data. '%s'", sqlite3_errmsg(database));
    else
        //SQLite provides a method to get the last primary key inserted by using sqlite3_last_insert_rowid
        //noteID = sqlite3_last_insert_rowid(database);

        //Reset the delete statement.
        sqlite3_reset(deleteStatement);
    sqlite3_close(database);
    deleteStatement = nil;
}   
else
    sqlite3_close(database);

}

Answer 2

关于SQL字符串......

delete from assets where assetBarcode=\"%@\'

参数正在使用报价打开，并以单引号关闭。两者都使用双引号或单引号。也许这与您的问题有关？

从SQLite数据库中删除行

2 个答案: