导致虽然mio_log表的mio_date、plnmio_date字段,以及freph_a01_fromtask3表的in_force_date字段上均有索引,但是由于两表不同字段进行CASE WHEN比较,执行计划为聚集索引扫描:优化思路:由于mio_log表的mio_date、plnmio_date字段,以及freph_a01_fromtask3表的in_force_date字段上均有索引,可先通过单个mio_date、...
CASE WHEN pref_name in ('德岛', '香川', '爱媛', '高知') THEN '九州' WHEN pref_name in ...
OR ） CASE WHEN sex = ‘1’ THEN ‘男’ WHEN sex = ‘2’ THEN ‘女’ ELSE ‘其他’ END...
问Oracle SQL不同的where子句with case whenEN愚蠢的问题，因为我想用where子句的两个选项开始一条select...
SQL union and minusSQL case when can use "in"、"not in" judge in case when clause can execute simple calculation in case when clause, eg : case when 1 = 1 then field_1 + field_2 else 0 endSQL if select if(sex='1','男','女') from t_user; ...
2) Case:a) If the value of the <search condition> of some <searched when clause> in a <...
Can I use a COLLATE clause in a temp table definition? Can I use aggregate function within CASE? Can I use if statement in a table valued function? Can I use LEN or DATALENGTH in a WHERE clause? Can I use OUTER JOIN on 2 columns at the same time? Can row_number() work in UNION...
SQL CASE WHEN语句性能优化,背景:性能应该是功能的一个重要参考,特别是在大数据的背景之下!写SQL语句时如果仅考虑业务逻辑,而不去考虑语句效率问题,有可能导致严重的效率问题,导致功能不可用或者资源消耗过大。其中的一种情况是,处理每日增量数据的程序,实际执行过
Text Field in Where clause condition In the above examples, we have seen that when the condition required numeric values in conditions such as employee salary & employee age, we didn’t require the quotes. However when the condition involves a column that has text value then in such case we...
WHERE last_name = 'Anderson' AND employee_id >= 3000; This SQL Server WHERE clause example uses the WHERE clause to define multiple conditions. In this case, this SELECT statement uses theAND conditionto return allemployeesthat have alast_nameof 'Anderson' and theemployee_idis greater than or...