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、...
In SQL Server 2008 it ispossible to use the undocumented and unsupported%%physloc%%virtual column to see this. Thisreturns abinary(8)value with the Page ID in the firstfour bytes, then 2 bytes for File ID, followed by 2 bytes for the slot locationon the page. The scalar functionsys.fn_...
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...
EXISTS in a WHERE Clause Using an EXISTS function call in a WHERE clause is probably the most common use case. The function will work exactly the same as in each earlier example, but there is one noticeable change. The subquery will almost always reference a column in a table that is oth...
SQL 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; ...
解决方法:如果是to_char、to_date或to_timestamp等函数,可以在SQL前通过设置GUC参数hg_experimental_functions_use_pg_implementation以支持更大范围的时间。详情请参见日期和时间函数。 报错:Group by key is type of imprecise not supported 问题原因:GROUP BY的字段类型是非精确类型,导致出现报错。
CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING. ...
Let's look at how to use the WHERE clause with the AND condition. For example: SELECT * FROM employees 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...
(Default50)rows--numberofrowsinconventional path bind array or between direct path datasaves(Default:Conventional path250,Direct path all)bindsize--sizeofconventional path bind arrayinbytes(Default1048576)silent--suppress messages duringrun(header,feedback,errors,discards,partitions)direct--use directpath...
Operators allowed in The WHERE Clause conditions In the above examples we have seen that where clause allowed operators as > & =. Lets see the complete list of operators that we can use in the where clause. Operators List: >Greater than operator ...