1Z0-007多项选择题每日一练(2020.04.06)

A. A single row subquery can retrieve data from only one table.
B. A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.
C. A SQL query statement can display data from table B that is referred to in its subquery, without including B in its own FROM clause.
D. A single row subquery can retrieve data from more than one table.
E. A single row subquery cannot be used in a condition where the LIKE operator is used for comparison.
F. A multiple-row subquery cannot be used in an INSERT statement to insert multiple rows at a time.

A. It releases the storage space used by the table.
B. It does not release the storage space used by the table.
C. You can roll back the deletion of rows after the statement executes.
D. You can NOT roll back the deletion of rows after the statement executes.
E. An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.
F. You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table

A.It releases the storage space used by the table.
B.It does not release the storage space used by the table.
C.You can roll back the deletion of rows after the statement executes.
D.You can NOT roll back the deletion of rows after the statement executes.
E.An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.
F.You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table.

A. You cannot roll back this statement.
B. All pending transactions are committed.
C. All views based on the DEPT table are deleted.
D. All indexes based on the DEPT table are dropped.
E. All data in the table is deleted, and the table structure is also deleted.
F. All data in the table is deleted, but the structure of the table is retained.
G. All synonyms based on the DEPT table are deleted.

A.INSTR returns the numeric position of a named character.
B.NVL2 returns the first non-null expression in the expression list.
C.TRUNCATE rounds the column, expression, or value to n decimal places.
D.DECODE translates an expression after comparing it to each search value.
E.TRIM trims the heading or trailing characters (or both) from a character string.
F.NVL compares two expressions and returns null if they are equal, or the first expression if they are not equal.
G.NULLIF compares two expressions and returns null if they are equal, or the first expression if they are not equal.