Microsoft SQL Server Database Quiz Questions

While having a unique identifier is good practice, it's not a requirement for each row. However, using primary keys is recommended for uniqueness.

SQL Server supports default values for columns, which are used when no value is provided during data insertion.

SQL Server allows modification of a column's data type using the ALTER TABLE command.

The ROW_NUMBER() function generates a unique sequential integer for rows within a result set.

By default, SQL Server allows NULL values in columns unless specified otherwise using the NOT NULL constraint.

SQL Server supports the IDENTITY property for columns to automatically increment values.

The ALTER TABLE command can be used to add new columns to an existing table in SQL Server.

The UNIQUE constraint ensures that all values in a column are distinct across the table.

Each column in a table must have a unique name to avoid ambiguity and ensure proper data management.

SQL Server supports a wide range of data types, including user-defined types for more customized data handling.

COUNT(*) counts all rows in a table, regardless of NULL values in any columns.

Default values for columns can be set both at the time of table creation and later using the ALTER TABLE command.

The DISTINCT keyword removes duplicate rows from the result set of a query in SQL Server.

SQL Server allows altering a column's data type even if it contains existing data, provided the conversion is valid.

Rows and columns in SQL Server tables are not inherently ordered by their insertion sequence. Ordering is controlled by the query results using ORDER BY.

The COUNT(*) function returns the total number of rows in a table.

The ALTER TABLE command with the ADD COLUMN clause is used to add a new column to an existing table.

The WHERE clause is used to filter rows in a query based on specified conditions.

The PRIMARY KEY constraint ensures that the values in a column are unique and not NULL, providing a unique identifier for each row.

The GETDATE() function retrieves the current date and time from the system.

The LEN() function calculates the number of characters in a string, excluding trailing spaces.

The ORDER BY clause is used to sort the result set based on one or more columns.

The AVG() function calculates the average value of a numeric column.

The DISTINCT keyword removes duplicate rows from the result set of a query.

The CONCAT() function is used to concatenate two or more strings into one string.

A SELECT statement without a WHERE clause retrieves all rows from the specified table.

The TRUNCATE TABLE command deletes all rows from a table but preserves its structure for future use.

The SELECT keyword is used to specify which columns to retrieve in a query.

The UPPER() function converts all characters in a string to uppercase.

The ROUND() function is used to round a numeric value to the specified number of decimal places.

Functions like SUM(), AVG(), COUNT(), and MAX() are used to aggregate data in SQL Server.

SQL Server supports various data types including INT, VARCHAR, DATE, and DECIMAL.

The ORDER BY clause is used to sort results, and GROUP BY is used to aggregate data in groups.

Column data can be modified using UPDATE statements and altered using ALTER TABLE commands.

Functions like GETDATE(), DATEADD(), and DATEDIFF() are used for manipulating and working with dates in SQL Server.

Constraints like PRIMARY KEY, FOREIGN KEY, and UNIQUE ensure data integrity by enforcing rules on columns.

Commands like DELETE and TRUNCATE TABLE are used to remove data from tables, with DELETE being more granular and TRUNCATE being more efficient for large data sets.

Using UNIQUE constraints and PRIMARY KEYS ensures that data in a column or combination of columns is unique.

Functions like CONCAT(), LEN(), and UPPER() are used for string manipulation in SQL Server.

Keywords like UNION and JOIN are used to combine and manipulate results from multiple queries.

Functions like CAST() and CONVERT() are used to change data types in SQL Server.

FOREIGN KEY constraints ensure referential integrity by enforcing relationships between tables.

Functions like GETDATE() and SYSDATETIME() return the current system date and time.

The CREATE TABLE command is used to define and create a new table, while ALTER TABLE can modify it afterward.

Functions like ISNULL() and COALESCE() are used to handle NULL values and provide default values.