子查询是我推荐的标准解决方案。基于级联的解决方案，除了在出现危险字符时容易出错之外，性能也可能更差。
Add auditing rule RuleCountDistinctMultiColumnsWarning. Add auditing rule RuleDiffOrderingSpecTypeWarning. Add auditing rule RuleUpDeleteWithLimitWarning. Add auditing rule RuleCrossJoinWarning. Add auditing rule RuleNaturalJoinWarning. Add auditing rule RuleStraightJoinWarning. Add rewrite ...
ForeignKeyColumns 展開資料表 ColumnNameDataType描述 OWNERString條件約束定義的擁有人。 CONSTRAINT_NAMEString條件約束定義的名稱。 TABLE_NAMEString具有條件約束定義的資料表名稱。 COLUMN_NAMEString條件約束定義中指定之物件型別資料行的資料行或屬性名稱。
In the past, classic reports rendered when the result set contained multiple columns with the same name. In Application Express 18.1, the column names of the query result set must be unique, otherwise a "Column Ambiguously Defined" error occurs. You must change any non-unique report queries pr...
COUNT DISTINCT with CHAR type uses binary sorting order and binary comparison semantics even when the NLSSORT attribute was set to a value different than binary. When the NLS_SORT session parameter is set to a multilingual sort (for example, FRENCH_M), the LIKE operator may produce incorrect ...
Locate COUNT_DISTINCT_SUPPORTED and uncheck the Value field. 11. Click OK to close the Database dialog box. 12. Double-click the Connection Pool for the Excel data source to open the Connection Pool dialog box. 13. Click the General tab and uncheck the property Enable connection pooling...
You can define up to ten distinct date attributes for any given lot or serial number that reflects item information you capture This information is stored in the D_ATTRIBUTE1 through D_ATTRIBUTE10 columns on the MTL_LOT_NUMBERS and MTL_SERIAL_NUMBERS tables. Character Attributes One category of...
oracle数据库才会给我们统计基于表的统计信息 --在指定for all columns 和不指定任何参数的时候oracle会给所有字段做统计信息,在指定for indexed columns时,oracle只给[b]有索引的字段进行字段信息统计[/b],如果我们别有必要给所有字段统计信息时,这个属性就很有用了. --再综合前面的我们就会发现,如果在运行analyze...
Oracle DISTINCT Statement on Multiple Columns After the Oracle DISTINCT keyword, it is possible to specify more than one column. The Oracle DISTINCT qualifier affects all selected columns, in so doing, the result will display the unique combination of values from the different columns. For example...
distinct; 使用表达式定义的字段; 伪列rownum; 原表在视图中未选择(未select)的字段的所有数据为非空且无默认值。 当然,并非只要SQL语句中包含了这6个子句或条件,就无法对视图进行全部DML。规则如下: 删除视图记录。要求SQL语句中不能包含前3个子句或条件。