單項選擇題

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.

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單項選擇題

Consider the following table called EMPLOYEES: ID FIRSTNAME LASTNAME JOB LEVEL
CLERK 3
If the following SQL statement is executed, how many rows will be deleted? DELETE FROM employees WHERE 1 = 1（）

A.0
B.1
C.3
D.6

單項選擇題

Which of the following is a feature of a unit of work?（）

A.It applies to a single data server.
B.It is a recoverable sequence of operations.
C.Its value can be queried from the system catalog tables.
D.It begins when the application connects to the data server.

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

你可能感興趣的試題

Consider the following table called EMPLOYEES: ID FIRSTNAME LASTNAME JOB LEVEL CLERK 3 If the following SQL statement is executed, how many rows will be deleted? DELETE FROM employees WHERE 1 = 1（）

Which of the following is a feature of a unit of work?（）

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Consider the following table called EMPLOYEES: ID FIRSTNAME LASTNAME JOB LEVEL
CLERK 3
If the following SQL statement is executed, how many rows will be deleted? DELETE FROM employees WHERE 1 = 1（）