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
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 identical column names.
D
The FROM clause contains two or more tables in the SELECT statement.