单选题In which of the following situations should correlation names be used?（）A A table referenced in the FROM clause has no indexed column.B The table referenced in the FROM clause has more than 200 columns.C Two or more tables in the FROM clause have ident

题目内容(请给出正确答案)

单选题

In which of the following situations should correlation names be used?（）

A table referenced in the FROM clause has no indexed column.

The table referenced in the FROM clause has more than 200 columns.

Two or more tables in the FROM clause have identical column names.

The FROM clause contains two or more tables in the SELECT statement.

如果没有搜索结果或未解决您的问题，请直接联系老师获取答案。

更多相关问题

第1题

In which four clauses can a subquery be used? ()A. in the INTO clause of an INSERT statementB. in the FROM clause of a SELECT statementC. in the GROUP BY clause of a SELECT statementD. in the WHERE clause of a SELECT statementE. in the SET clause of an UPDATE statementF. in the VALUES clause of an INSERT statement

点击查看答案
第2题

In which of the following situations should correlation names be used?()A.A table referenced in the FROM clause has no indexed column.B.The table referenced in the FROM clause has more than 200 columns.C.Two or more tables in the FROM clause have identical column names.D.The FROM clause contains two or more tables in the SELECT statement.

点击查看答案
第3题

Which two statements are true regarding the USING clause in table joins?（）A、It can be used to join a maximum of three tables B、It can be used to restrict the number of columns used in a NATURAL join C、It can be used to access data from tables through equijoins as well as nonequijoins D、It can be used to join tables that have columns with the same name and compatible data types

点击查看答案
第4题

In which of the following situations should correlation names be used?（）A、A table referenced in the FROM clause has no indexed column.B、The table referenced in the FROM clause has more than 200 columns.C、Two or more tables in the FROM clause have identical column names.D、The FROM clause contains two or more tables in the SELECT statement.

点击查看答案
第5题

In which case would you use a FULL OUTER JOIN?（）A、Both tables have NULL values.B、You want all unmatched data from one table.C、You want all matched data from both tables.D、You want all unmatched data from both tables.E、One of the tables has more data than the other.F、You want all matched and unmatched data from only one table.

点击查看答案
第6题

Which two are true about aggregate functions? （）A、You can use aggregate functions in any clause of a SELECT statement.B、You can use aggregate functions only in the column list of the select clause and in the WHERE clause of a SELECT statement.C、You can mix single row columns with aggregate functions in the column list of a SELECT statement by grouping on the single row columns.D、You can pass column names, expressions, constants, or functions as parameter to an aggregate function.E、You can use aggregate functions on a table, only by grouping the whole table as one single group.F、You cannot group the rows of a table by more than one column while using aggregate functions.

点击查看答案
第7题

In which four clauses can a subquery be used? （）A、in the INTO clause of an INSERT statementB、in the FROM clause of a SELECT statementC、in the GROUP BY clause of a SELECT statementD、in the WHERE clause of a SELECT statementE、in the SET clause of an UPDATE statementF、in the VALUES clause of an INSERT statement

点击查看答案

单选题In which of the following situations should correlation names be used?（）A A table referenced in the FROM clause has no indexed column.B The table referenced in the FROM clause has more than 200 columns.C Two or more tables in the FROM clause have ident

题目内容(请给出正确答案)

更多相关问题

第1题

第2题

第3题

第4题

第5题

第6题

第7题

相关内容