Introduction To Sql - Study Mode

[#6] To define what columns should be displayed in an SQL SELECT statement:
Correct Answer

(A) use FROM to name the source table(s) and list the columns to be shown after SELECT.

Explanation

Solution: Option A: use FROM to name the source table(s) and list the columns to be shown after SELECT. - This option is incorrect. The "FROM" clause is used to specify the table(s) from which data is retrieved, not to define columns to be displayed. Option B: use USING to name the source table(s) and list the columns to be shown after SELECT. - This option is incorrect. The "USING" clause in SQL is used for specifying columns for join conditions, not for selecting columns to display. Option C: use SELECT to name the source table(s) and list the columns to be shown after USING. - This option is incorrect. The "SELECT" keyword is used at the beginning of a query to specify the columns or expressions to be retrieved, not to name tables or specify columns after "USING". Option D: use USING to name the source table(s) and list the columns to be shown after WHERE. - This option is incorrect. The "USING" keyword in SQL is not used to list columns to be displayed in a SELECT statement. Conclusion: To define what columns should be displayed in an SQL SELECT statement, you use the Option A: use FROM to name the source table(s) and list the columns to be shown after SELECT. This means you specify the columns to display immediately after the "SELECT" keyword, not after "FROM" or "USING". Therefore, the correct answer is Option A .

[#7] SQL can be used to:
Correct Answer

(D) All of the above can be done by SQL.

Explanation

Solution: Option A: create database structures only. - This option is incorrect. SQL (Structured Query Language) can do more than just create database structures. It can also query data and modify data. Option B: query database data only. - This option is incorrect. SQL is not limited to querying data only. It can also create database structures and modify data. Option C: modify database data only. - This option is incorrect. SQL is not limited to modifying data only. It can also create database structures and query data. Option D: All of the above can be done by SQL. - This is the correct answer. SQL is a comprehensive language that can perform various tasks including creating database structures (DDL - Data Definition Language), querying database data (DML - Data Manipulation Language), and modifying database data. Conclusion: SQL can be used for Option D: All of the above can be done by SQL. This includes creating database structures, querying database data, and modifying database data. Therefore, the correct answer is All of the above can be done by SQL.

[#8] The SQL statement that queries or reads data from a table is ________ .
Correct Answer

(A) SELECT

Explanation

Solution: Option A: SELECT - This is the correct answer. The "SELECT" statement in SQL is used to query or read data from a table. It allows you to specify which columns to retrieve and from which table. Option B: READ - This option is incorrect. "READ" is not a standard SQL keyword used for querying data from a table. Option C: QUERY - While "QUERY" can be used informally to describe retrieving data, it is not a specific SQL keyword for reading data from a table. Option D: None of the above is correct - This option is incorrect because Option A ("SELECT") is indeed the correct SQL keyword for querying or reading data from a table. Conclusion: The SQL statement that queries or reads data from a table is Option A: SELECT . This keyword is fundamental in SQL for retrieving data from one or more tables. Therefore, the correct answer is SELECT .

[#9] The SQL keyword(s) ________ is used with wildcards.
Correct Answer

(A) LIKE only

Explanation

Solution: Option A: LIKE only - The LIKE keyword in SQL is used with wildcards to search for a specified pattern in a column. This option correctly identifies the keyword used with wildcards. Option B: IN only - The IN keyword is used to specify multiple values for a column, not with wildcards. Option C: NOT IN only - The NOT IN keyword is used to exclude specified values from a column, not with wildcards. Option D: IN and NOT IN - Both IN and NOT IN are used to specify values or exclude values from a column, not with wildcards. Conclusion: In SQL, the keyword LIKE is specifically used with wildcards to perform pattern matching in a column. Therefore, the correct answer is Option A: LIKE only .

[#10] Which of the following is the correct order of keywords for SQL SELECT statements?
Correct Answer

(A) SELECT, FROM, WHERE

Explanation

Solution: Option A: SELECT, FROM, WHERE - This option presents the correct order of keywords for a SQL SELECT statement: SELECT : Specifies the columns to retrieve data from. FROM : Specifies the table from which to retrieve data. WHERE : Optional clause that specifies conditions to filter rows. Option B: FROM, WHERE, SELECT - Incorrect order. The SELECT keyword should come before FROM to specify the columns to select.

Option C: WHERE, FROM, SELECT - Incorrect order. The SELECT keyword should come before FROM to specify the columns to select.

Option D: SELECT,WHERE,FROM - Incorrect order. The FROM keyword should come after SELECT to specify the table from which to select data. Conclusion: The correct order of keywords for a SQL SELECT statement is Option A: SELECT, FROM, WHERE .