发布网友 发布时间:2022-04-25 23:39
共3个回答
懂视网 时间:2022-04-30 09:38
makr 插入数据 - (void)insetIntoTableWithID:(int)nameID withName:(NSString *)name withSex:(NSString *)sex withBook:(Book *)abook { // 对abook进行归档(先归档) NSMutableData *data = [NSMutableData data]; NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data]; [archiver encodeObject:abook forKey:abook.bookName]; // abook.bookName***key不能一样否则会覆盖 [archiver finishEncoding]; // sql语句 NSString *sqlString = [NSString stringWithFormat:@"INSERT INTO ‘user_hh‘(‘id‘,‘name‘,‘sex‘,‘book‘)VALUES(?, ?, ?,?)"]; sqlite3_stmt *stmt = nil; int result = sqlite3_prepare(db, [sqlString UTF8String], -1, &stmt, NULL); if (result == SQLITE_OK) { // 绑定字段 // sql里面写了字段,字段从一开始 sqlite3_bind_int(stmt, 1, nameID); sqlite3_bind_text(stmt, 2, [name UTF8String], -1, NULL); sqlite3_bind_text(stmt, 3, [sex UTF8String], -1, NULL); sqlite3_bind_blob(stmt, 4, [data bytes], (int)[data length], NULL); // 执行 sqlite3_step(stmt); } // 结束 sqlite3_finalize(stmt); // 插入语句 /* NSString *insertSql = [NSString stringWithFormat:@"INSERT INTO ‘user_hh‘(‘id‘,‘name‘,‘sex‘,‘book‘)VALUES(‘%d‘, ‘%@‘, ‘%@‘,‘%@‘)",nameID,name,sex,data]; // 执行SQL语句 int result = sqlite3_exec(db, [insertSql UTF8String], NULL, NULL, NULL); if (result == SQLITE_OK) { NSLog(@"插入成功"); }else{ NSLog(@"插入失败"); } */ }2.查询数据库
#pragma mark 查询数据库 - (void)selectDataFromTable { NSString *selectSql = [NSString stringWithFormat:@"SELECT *FROM ‘user_hh‘"]; // 保存查询到的结果集 sqlite3_stmt *stmt = nil; // 准备查询数据(预存取) int result = sqlite3_prepare(db, [selectSql UTF8String], -1, &stmt, NULL); if (result == SQLITE_OK) { // 判断是否是最后一行,有没有必要继续下去 // 这里用while循环 一行一行执行 ******不用if****** while(sqlite3_step(stmt) == SQLITE_ROW) { // 拿出各列的数据 // 1.拿出id列的数据 int numberID = sqlite3_column_int(stmt, 0); // 2.拿出name列的数据 const unsigned char *nameChar = sqlite3_column_text(stmt, 1); NSString *name = [NSString stringWithUTF8String:(const char *)nameChar]; // 3.拿出sex列的数据 const unsigned char *sexChar = sqlite3_column_text(stmt, 2); NSString *sex = [NSString stringWithUTF8String:(const char *)sexChar]; // 4.拿出BOOK列 ******桥接****** // NSData *data = (__bridge NSData *)(sqlite3_column_blob(stmt, 3)); const void *bytes = (sqlite3_column_blob(stmt, 3)); int length = sqlite3_column_bytes(stmt, 3); NSData *data = [[NSData alloc] initWithBytes:bytes length:length]; // 反归档 NSKeyedUnarchiver *unArchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data]; Book *thisBook = [unArchiver decodeObjectForKey:@"西游记"]; [unArchiver finishDecoding]; // 结束反归档 NSLog(@"%d %@ %@ %@",numberID,name,sex,thisBook.bookName); } // 结束查询 --- 重要 ****** 否则无法关闭数据库****** sqlite3_finalize(stmt); } }
3.这里BOOK类对属性需要编码和反编码(NSCoding协议)
-(void)encodeWithCoder:(NSCoder *)aCoder { [aCoder encodeObject:self.bookName forKey:@"bookName"]; } -(id)initWithCoder:(NSCoder *)aDecoder { self = [super init]; if (self) { self.bookName = [aDecoder decodeObjectForKey:@"bookName"]; } return self; }
SQLite数据库---将复杂对象存入数据库
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热心网友 时间:2022-04-30 06:46
具体的操作步骤如下:热心网友 时间:2022-04-30 08:04
一、用sqlite命令