ios - 如何在 sqlite iOS 中查找现有文件夹名称

Question

我创建了一个表，其中只有几个字段是唯一的。因此，当用户将重复的文件夹名称插入表中时，我必须向他们显示警报。谁能告诉我“如何在将现有数据插入到 sqlite 数据库的表中之前检查现有数据”

Answer 1

可以通过以下代码查看记录

-(BOOL)CheckForRecord:(NSString *)Name
{
    BOOL isRecordPresent=false;

    const char *dbpath = [databasePath UTF8String];
    sqlite3_stmt    *statement;

    if (sqlite3_open(dbpath, &database) == SQLITE_OK)
    {
        NSString *querySQL = [NSString stringWithFormat:
                              @"SELECT ID FROM TBL_Name WHERE Column_Name=\"%@\"",Name];

        const char *query_stmt = [querySQL UTF8String];

        if (sqlite3_prepare_v2(database,
                               query_stmt, -1, &statement, NULL) == SQLITE_OK)
        {
            if(sqlite3_step(statement) == SQLITE_ROW)
            {
                isRecordPresent = 1;
            }
            else
            {
                isRecordPresent = 0;
            }
        }
    }

    sqlite3_finalize(statement);
    if(sqlite3_close(database) == SQLITE_OK)
    {

    }
    else
    {
        NSAssert1(0, @"Error: failed to close database on memwarning with message '%s'.", sqlite3_errmsg(database));
    }   
    return isRecordPresent;
}