Database and SQL

ORDER BY is the correct clause for sorting, and DESC specifies descending order. The column name should not be quoted, and the keyword is ORDER BY not SORT BY.

INSERT INTO table VALUES (values) is the standard SQL syntax for inserting a complete row. The table name must come after INSERT INTO, and VALUES must precede the actual values.

INSERT INTO table (column) VALUES (value) is the correct syntax for inserting into specific columns. The column list in parentheses must come before VALUES.

UPDATE table SET column=value WHERE condition is the correct syntax. SET assigns the new value, and WHERE specifies which rows to update based on the old value.

DELETE FROM table WHERE condition removes rows matching the condition. The WHERE clause is essential to specify which rows to delete.

COUNT(*) is the aggregate function that returns the total number of rows in a table. COLUMNS is not a valid SQL function for counting.

COUNT(*) returns the total number of rows. The table has 3 rows (a1 bob NULL, b1 jim a1, B2 tom a1), so the answer is 3.

SELECT statements return all matching rows by default, including duplicates. DISTINCT must be explicitly used to remove duplicate rows.

To solve this question, one needs to understand the difference between count(*) and count(column_name).

count(*) returns the total number of rows in the table, whereas count(column_name) returns the number of non-null values for the given column.

Now, let's go through each option and explain why it is right or wrong:

A. True: This option is false. count(*) will always return the same value as the number of rows in the table, while count(column_name) will return the number of non-null values for the given column. Thus, it is possible for count(column_name) to return a higher value than count(*), but not a lower value.

B. False: This option is correct. count(*) returns the total number of rows in the table, whereas count(column_name) returns the number of non-null values for the given column. Thus, it is not possible for count(column_name) to return fewer rows than count(*).

The Answer is: B

An EXCLUSIVE lock is used for data-modification operations. It prevents any other transaction from acquiring any type of lock on the resource (table or page) until the exclusive lock is released, effectively denying all other access.

DELETE is the SQL command for removing rows from a table. DROP removes entire tables, and REMOVE ROW is not valid SQL syntax.

SQL supports multiple join syntaxes including the older WHERE-style joins (theta style) and the ANSI standard JOIN...ON syntax, so the statement is false.

Outer joins include LEFT OUTER JOIN, RIGHT OUTER JOIN, and FULL OUTER JOIN. Since both right and full outer joins exist, 'all of the above' is correct.

To solve this question, the user needs to know that the LEFT function extracts a specified number of characters from the left side of a given string. The CAST function converts a given expression to a specified data type. The LEN function returns the number of characters in a given string.

In this case, the LEFT function is extracting the first three characters from the string '026-100', which results in '026'. The CAST function is converting this string to an integer data type, resulting in the value 26. The LEN function then determines the number of characters in the resulting string, which is 2. Therefore, the correct answer is:

The Answer is: B. 2

To solve this question, the user needs to know about the SMALLDATETIME data type and how to cast values to it.

In SQL Server, SMALLDATETIME is a data type that stores a date and time with a precision of one minute. It is represented as a two-byte signed integer.

The CAST function is used to convert one data type to another. In this case, the value -1 is being cast to the SMALLDATETIME data type.

Now, let's go through each option and explain why it is right or wrong:

A. 1900-01-01 00:00:00.000: This option is incorrect because the SMALLDATETIME data type has a minimum value of 1900-01-01 00:00:00. The value -1 is less than the minimum value, so it cannot be converted to a SMALLDATETIME.

B. 1899-01-01 00:00:00.000: This option is incorrect because the SMALLDATETIME data type has a minimum value of 1900-01-01 00:00:00. The value -1 is less than the minimum value, so it cannot be converted to a SMALLDATETIME.

C. 1752-01-01 00:00:00.000: This option is incorrect because the SMALLDATETIME data type has a minimum value of 1900-01-01 00:00:00. The value -1 is less than the minimum value, so it cannot be converted to a SMALLDATETIME.

D. The system will generate an error. Only positive integer values can be converted to a SMALLDATETIME data type: This option is incorrect because the SMALLDATETIME data type can store both positive and negative integer values. However, the value -1 is less than the minimum value of the SMALLDATETIME data type, so it cannot be converted to a SMALLDATETIME.

The Answer is: D