SQL查询中的NOT IN操作符用于从一个查询结果中排除包含在另一个查询结果中的值。但在使用NOT IN时,有可能会遇到一些错误。 错误可能的原因包括: 空值(NULL)的存在:如果查询结果中包含NULL值,NOT IN操作符可能会返回错误结果。这是因为NULL与其他任何值的比较结果都是未知的,所以在使用NOT IN时应特别注意处理NULL...
A condition that evaluates to UNKNOWN acts almost like FALSE.For example, a SELECT statement with a condition in the WHERE clausethat evaluates toUNKNOWN returns no rows. However, a condition evaluatingto UNKNOWN differs from FALSE in that further operations onan UNKNOWN condition evaluation will eva...
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前段时间碰到一个慢 SQL,NOT IN 子查询被优化器改写成了 NESTED-LOOP ANTI JOIN,但是被驱动表全表扫描无法使用索引,执行耗时 16 秒。SQL 如下: SELECTAGENT_ID,MAX(REL_AGENT_ID)FROMT_LDIM_AGENT_UPRELWHEREAGENT_IDNOTIN(selectAGENT_IDfromT_LDIM_AGENT_UPRELwherevalid_flg='1')groupbyAGENT_ID; 简略...
Simple Example of SQL NOT IN Using our sample data of food, let’s say you wanted to find foods that were not fruit. So, you want to see records that were not Apple, Banana, or Pear. A query to do that could look like this: ...
为了得到更多的信息,使用explain extended查看NOT INsql 语句的执行计划,然后接着执行show warnings看到如下内容: /* select#1 */select`example`.`USERS`.`ID`AS`ID`from`example`.`USERS`where((`example`.`USERS`.`ID`in(1,7,2431,87142,32768))and(not((`...
in 的示例: Notice that the null value as part of the results set of a subquery is not a problem if you use the IN operator. The IN operator is equivalent to =ANY. For example, to display the employees who have subordinates(下属), use the following SQL statement: ...
true if the value is found in the collection; null if the value is null or the collection is null; otherwise, false. Using NOT IN negates the results of IN.ExampleThe following Entity SQL query uses the IN operator to determine whether a value matches any value in a collection. The ...
SQL> insertinto emp(empno,ename) values(8888,'Dave'); 1 row created. SQL>commit; Commitcomplete. 这里我们只插入了empno和ename,其他为空。 下面进行2张表的的操作: SQL> selectempno,ename from emp where job not in (select job from emp1); ...
SQL NOT IN with Numbers This next set of example queries is looking for account persons who have made exactly 6, 8, or 9 sales. Since the values are not concurrent, neither a BETWEEN operator nor a combination of arguments utilizing < and > will work. ...