第一个查询使用EXISTS而第二个查询使用IN。注意两个查询返回同样的信息。 USEpubs GO SELECTDISTINCTpub_name FROMpublishers WHEREEXISTS (SELECT* FROMtitles WHEREpub_id=publishers.pub_id ANDtype=/'business/') GO --Or, using the IN clause: USEpubs GO SELECTdistinctpub_name FROMpublishers WHEREpub_id...
How we work with data is also immensely important — if our database is optimized well (check one of our previous articles for advice on how to do that), we should not have that manyINorNOT INclauses to begin with. Even if we do, our SQL client of choice is usually capable of ass...
B. 比较使用EXISTS和IN的查询 这个例子比较了两个语义类似的查询。第一个查询使用EXISTS而第二个查询使用IN。注意两个查询返回相同的信息。 USEpubs GO SELECTDISTINCTpub_name FROMpublishers WHEREEXISTS (SELECT* FROMtitles WHEREpub_id=publishers.pub_id ANDtype=/'business/') GO --Or, using the IN clau...
SQL查询,NOT IN返回错误 、 我得到一个错误Unknown column in 'where clause。 SELECT * FROM invoices where `desc`='Invoice from mr.Robot' NOT IN (SELECT * FROM invoices where robot_calls.invoice_id=invoices.id)"; 我不是sql专家,有人能给我点亮吗? 浏览41提问于2018-01-05得票数 2 回答已采...
在运行sql语句时,出现以下问题: [Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated c 原因: MySQL 5.7.5及以上功能依赖检测功能。如果启用了ONLY_FULL_GROUP_BY SQL模式(默认情况下),MySQL将拒绝选择列表,HAVING条件或ORDER BY列表的查询引用在GROUP BY子句...
[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated c 原因: MySQL 5.7.5及以上功能依赖检测功能。如果启用了ONLY_FULL_GROUP_BY SQL模式(默认情况下),MySQL将拒绝选择列表,HAVING条件或ORDER BY列表的查询引用在GROUP BY子句中既未命名的非集合列,也不在功...
BY clause and contains nonaggregated column 'mydb.t.address' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by If you know that,for a given data set,eachnamevalue in fact uniquely determines theaddressvalue,addressis effect...
其实采用哪种方法只是一种偏好问题,但是我认为大多数人会觉得使用not in版本的查询更好理解。 注意:使用not in或<> all将值与值集进行比较时,必须确保值集不包含null值,因为服务器会将表达式左侧的值与集合的每个成员进行判等操作,而任何试图将值与null值进行比较的操作都会产生未知的结果。因此,以下查询返回一个...
where.c- This file (together with its helper files named by "where*.c") analyzes the WHERE clause and generates virtual machine code to run queries efficiently. This file is sometimes called the "query optimizer". It has its own private header file, whereInt.h, that defines data objects ...
The OUTPUT INTO clause is not supported in INSERT statements that contain a <dml_table_source> clause. For more information about the arguments and behavior of this clause, see OUTPUT Clause (Transact-SQL).VALUES Introduces the list or lists of data values to be inserted. There must be one...