Which of the following is incorrect in SQL?

Which of the following is incorrect SQL?

Discussion Forum

Que. Which of the following is correct:
b. SQL permits attribute names to be repeated in the same relation.
c. a SQL query will not work if there are no indexes on the relations
d. None of these
Answer:None of these

Which of the following is correct a SQL query will not work if there are no indexes on the relations?

Explanation: The SQL query will work even when there are no indexes on the relations. It is because SQL query could generate index automatically even when there is no indication of indexes. In this context, the index is commonly used for speeding up the presentation of queries in SQL.

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What is the purpose of the SQL AS clause?

The AS clause in SQL is used to change the column name in the output or assign a name to a derived column.

Why we need to create an index if the primary key is already present in a table?

32) Why we need to create an index if the primary key is already present in a table? Primary key can store null value, whereas a unique key cannot store null value.

Which of the following is the correct order of a SQL statement?

Detailed Solution. The correct answer is Select, where, group by, having.

Which of the following is correct a SQL query automatically eliminate duplicates?

Explanation: An SQL does not remove duplicates like relational algebra projection, we have to remove it using distinct. An SQL will work slowly but surely if there are no indexes. An SQL does not permit 2 attributes of same name in a relation.

Which of the following is not a type of database?

Answer: folder database is not a type of database.

Which of the following is correct SQL permits attributes?

the answer is b . SQL permits attribute names to be repeated in the same relation .

Is not a category of SQL command?

The correct answer to the question “________________ is not a category of SQL command” is option (b). SCL. Other categories of SQL commands are TCL, DCL, DDL, etc. but not SCL.

What is where clause in SQL?

A WHERE clause in SQL specifies that a SQL Data Manipulation Language (DML) statement should only affect rows that meet specified criteria. … In brief SQL WHERE clause is used to extract only those results from a SQL statement, such as: SELECT , INSERT , UPDATE , or DELETE statement.

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Which statement is wrong about primary key constraint in SQL?

Which statement is wrong about PRIMARY KEY constraint in SQL? Primary keys must contain UNIQUE values.

What is Oracle SQL called?

PL/SQL (Procedural Language for SQL) is Oracle Corporation’s procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 6 – stored PL/SQL procedures/functions/packages/triggers since version 7), Times Ten in-memory database (since version 11.2.

Which of the following is correct create index command?

Which of the following is correct CREATE INDEX Command? Explanation: The basic syntax of a CREATE INDEX is as follows : CREATE INDEX index_name ON table_name; 4. A ______ index is created based on only one table column.

Is primary key same as index?

The primary key are the column(s) that serves to identify the rows. An index is a physical concept and serves as a means to locate rows faster, but is not intended to define rules for the table.

Does primary key automatically create index?

Yes, primary key is automatically indexed in MySQL because primary key, index, etc gets stored into B-trees. … The primary key is implicitly indexed in InnoDB, MyISAM, and other engines.

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