//插入
Message *message = [[Message alloc] init];
message.localID = 1;
message.content = @"Hello, WCDB!";
message.createTime = [NSDate date];
message.modifiedTime = [NSDate date];
/*
INSERT INTO message(localID, content, createTime, modifiedTime)
VALUES(1, "Hello, WCDB!", 1496396165, 1496396165);
*/
BOOL result = [database insertObject:message
into:@"message"];
//刪除
//DELETE FROM message WHERE localID>0;
BOOL result = [database deleteObjectsFromTable:@"message"
where:Message.localID > 0];
//修改
//UPDATE message SET content="Hello, Wechat!";
Message *message = [[Message alloc] init];
message.content = @"Hello, Wechat!";
BOOL result = [database updateRowsInTable:@"message"
onProperties:Message.content
withObject:message];
//查詢
//SELECT * FROM message ORDER BY localID
NSArray<Message *> *message = [database getObjectsOfClass:Message.class
fromTable:@"message"
orderBy:Message.localID.order()];
事務(wù)一
BOOL commited = [database runTransaction:^BOOL {
[database insertObject:message into:@"message"];
return YES; //return YES to commit transaction and return NO to rollback transaction.
}];
事務(wù)二
WCTTransaction *transaction = [database getTransaction];
BOOL result = [transaction begin];
[transaction insertObject:message into:@"message"];
result = [transaction commit];
if (!result) {
[transaction rollback];
NSLog(@"%@", [transaction getError]);
}
事務(wù)（Transaction）哑舒，一般是指要做的或所做的事情。在計算機(jī)術(shù)語中是指訪問并可能更新數(shù)據(jù)庫中各種數(shù)據(jù)項的一個程序執(zhí)行單元(unit)淤袜。事務(wù)(Transaction)是訪問并可能更新數(shù)據(jù)庫中各種數(shù)據(jù)項的一個程序執(zhí)行單元(unit)。事務(wù)通常由高級數(shù)據(jù)庫操縱語言或編程語言（如SQL，C++或Java）書寫的用戶程序的執(zhí)行所引起作喘，并用形如begin transaction和end transaction語句（或函數(shù)調(diào)用）來界定厢蒜。事務(wù)由事務(wù)開始(begin transaction)和事務(wù)結(jié)束(end transaction)之間執(zhí)行的全體操作組成霞势。
