fmdb 数据库升级1-----增加表字段

//判断字段是否存在
        if ([self.db columnExists:kScanCardPath inTableWithName:TABLE_CARD]) {
            NSString *update = [NSString stringWithFormat:@"UPDATE %@ SET %@=? WHERE %@ = '%@'",TABLE_CARD,kScanCardPath,kLiuDuID,liuduid];
            [self.db executeUpdate:update,path];
        }else{
            NSString *sql = [NSString stringWithFormat:@"ALTER TABLE %@ ADD %@ text",TABLE_CARD,kScanCardPath];
            [self.db executeUpdate:sql];
            NSString *update = [NSString stringWithFormat:@"UPDATE %@ SET %@=? WHERE %@ = '%@'",TABLE_CARD,kScanCardPath,kLiuDuID,liuduid];
            [self.db executeUpdate:update,path];
        }

kScanCardPath，kLiuDuID<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">是字段的宏定义</span>

TABLE_CARD<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">是表名的宏定义</span>

注意：需包含头文件#import"FMDatabaseAdditions.h"