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 w
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...
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...
1055(42000): SELECT list is not in GROUP BY clause and contains nonaggregated column 原因与解决方案 该报错主要是因为sql_mode参数被修改导致: 原因一:用户修改sql_mode参数导致GROUP BY的语法不合规 原因:用户修改了sql_mode参数,添加了ONLY_FULL_GROUP_BY条件,导致GROUP BY的语法不...
p.amount -> FROM actors_s_pg spg -> INNER JOIN inventory i -> ON i.film_id = spg.film_id -> INNER JOIN rental r -> ON i.inventory_id = r.inventory_id -> INNER JOIN payment p -> ON r.rental_id = p.rental_id -> ) -- end of With clause -> SELECT spg_rev.first_name...
mysql> SELECT name, address, MAX(age) FROM t GROUP BY name; ERROR 1055 (42000): Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'mydb.t.address' which is not functionally dependent on columns in GROUP BY clause; this i...
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...
ERRCODE_NOT_NULL_VIOLATION或者not-null constraint或者UsageProblem 报错:null value in column "xxx" violates not-null constraint 问题原因:违反非空约束,NOT NULL的列写入了NULL值。 解决方法:去掉NULL的脏数据后再进行写入。 ERRCODE_UNDEFINED_TABLE
问SQL查询，NOT IN返回错误ENimport MySQLdb import json def getSql(): try: ...