Which of the following is a valid data type in SQL?a) textb) numberc) varchar(n)d) array

To determine which of the options is a valid data type in SQL, we can analyze each choice:

1. Option a: text - This is a valid data type in SQL, particularly in PostgreSQL and other SQL variants, used for storing string data of varying lengths.

2. Option b: number - This is not a standard SQL data type. While some SQL dialects might have numerical data types like INTEGER or FLOAT, "number" itself is not universally recognized in SQL.

3. Option c: varchar(n) - This is a valid data type in SQL. It specifies a variable-length string that can hold up to n characters. This is commonly used to store strings of varying lengths.

4. Option d: array - Arrays are not a standard data type in SQL. While some database systems (like PostgreSQL) support arrays as a data type, it is not universally applicable across all SQL databases.

Final Answer

The valid data types in SQL from the provided options are a) text and c) varchar(n).