SQL Multitables Quiz

Apakah tujuan menggunakan multi table pada SQL ?

• Meningkatkan data redudansi dan integritas data

• Menyederhanakan fungsi penyimpanan data SQL

• Meningkatkan keamanan data dan ancaman pada basis data

• Mengorganisir dan menyimpan data sesuai struktur, mengurangi redudansi data, dan menganalisis query dan data yang kompleks

Apakah yang dimaksud primary key pada tabel SQL ?

• Primary key adalah kolom yang digunakan untuk mengurutkan data dalam tabel SQL

• Primary key adalah kolom yang menyimpan data paling penting dalam tabel SQL

• Primary key adalah yang secara unik mengidentifikasi setiap baris dalam tabel SQL.

• Primary key adalah kolom yang digunakan untuk menghitung nilai rata-rata data dalam tabel SQL

How can you join two tables in SQL?

• Using the MERGE keyword and the ON keyword to specify the join condition.

• Using the UNION keyword to combine the tables.

• Using the GROUP BY keyword to group the tables together.

• Using the JOIN keyword and the ON keyword to specify the join condition.

What is the difference between INNER JOIN and OUTER JOIN?

• INNER JOIN returns all the rows from one table and the matching rows from the other table, while OUTER JOIN returns only the rows that have no matching values in the other table.

• INNER JOIN returns all the rows from both tables, while OUTER JOIN returns only the rows that have no matching values in the other table.

• INNER JOIN returns all the rows from one table and the matching rows from the other table, while OUTER JOIN returns only the matching rows between two tables.

• INNER JOIN returns only the matching rows between two tables, while OUTER JOIN returns all the rows from one table and the matching rows from the other table.

What is a foreign key in a SQL table?

• A foreign key is a column or a set of columns that references the primary key of another table.

• A foreign key is a column or a set of columns that stores the primary key of another table.

• A foreign key is a column or a set of columns that references the primary key of the same table.

• A foreign key is a column or a set of columns that references the secondary key of another table.

What is the purpose of using aliases in SQL queries?

• To allow multiple tables to have the same name in a query.

• To provide a temporary name or shorthand notation for a table or column.

• To improve the performance of the SQL queries.

• To hide sensitive information in the database.

What is the difference between UNION and UNION ALL in SQL?

• UNION ALL is used for combining tables vertically, while UNION is used for combining tables horizontally

• UNION and UNION ALL are the same and can be used interchangeably

• UNION removes duplicate rows, while UNION ALL includes all rows

• UNION ALL removes duplicate rows, while UNION includes all rows

What is a self-join in SQL?

• Joining a table with itself

• Joining a table with another table

• Joining a table with a different database

• Joining a table with a different column

What is the purpose of using subqueries in SQL?

• To delete data from the database.

• To retrieve data based on the result of another query.

• To update data in the database.

• To create new tables in the database.

What is the difference between DELETE and TRUNCATE in SQL?

• DELETE is a DML command used to delete specific rows, while TRUNCATE is a DDL command used to remove all rows from a table.

• DELETE is a DDL command used to remove all rows from a table, while TRUNCATE is a DML command used to delete specific rows.

• DELETE is a command used to remove all rows from a table, while TRUNCATE is a command used to delete specific columns.

• DELETE is a DDL command used to delete specific columns, while TRUNCATE is a DML command used to remove all rows from a table.