在Oracle数据库中,过程(Procedure)是一种存储在数据库中的程序,它可以执行一系列的SQL语句。过程可以包含输入参数、输出参数以及局部变量。当你在过程中使用两个`SELECT`语句时,通常...
而且，如果你能够理解它，直到以一种非嵌套的方式实现它，那么您也可以将该实现转换为嵌套实现。
'abc' as name union all select @id as id,'zzz' as name 返回两行数据. 现在想用SQL语句...
而且，如果你能够理解它，直到以一种非嵌套的方式实现它，那么您也可以将该实现转换为嵌套实现。
select @sql=isnull(@sql+',','') +'max(case m.ItemID when '''+Convert(varchar(5),ItemID)+''' then case when m.Result=1 then ''OK'' when m.Result=2 then ''未开机'' else ''NG'' end else ''NG'' end) '''+Convert(varchar(5),ItemID)+''' from...
5) we let InnoDB do locking reads for all SQL statements that are not simple SELECTs; note that select_lock_type in this case may get strengthened in ::external_lock() to LOCK_X. Note that we MUST use a locking read in all data modifying ...
SELECTsupports explicit partition selection using thePARTITIONclause with a list of partitions or subpartitions (or both) following the name of the table in atable_reference(seeSection 13.2.9.2, “JOIN Clause”). In this case, rows are selected only from the partitions listed, and any other pa...
I needed help once more. I have a select the query below from 1 table ( CashierSalesDetails) select TransactionNumber, sum (c.ConvertedNetPremium + c.ConvertedVAT + c.ConvertedRegistryFee) as AR f...
You can also select values from aVALUESstatement that generates a single row into a set of user variables. In this case, you must employ a table alias, and you must assign each value from the value list to a variable. Each of the two statements shown here is equivalent toSET @x=2, ...
(In my case the CREATE TEMPORARY line was produced by dynamic SQL, which I have excluded above for readability.) The trick is to use fixed field name aliases, so even if the underlying field names have changed, the DECLARE CURSOR line will always use the aliases....