Which SQL statement is used to make changes to the structure of an existing table without deleting it?OptionsALTER TABLEDELETE TABLEMODIFY TABLECHANGE TABLE

Break Down the Problem

1. Identify the SQL statement types mentioned.
2. Determine the purpose of each SQL statement in the context of modifying a table structure.

Relevant Concepts

• ALTER TABLE: Used to modify the existing structure of a table, such as adding, deleting, or modifying columns.
• DELETE TABLE: Not a valid SQL command for altering a table structure (commonly refers to deleting rows).
• MODIFY TABLE: Not a standard SQL command; the correct term in SQL is considered to be part of the ALTER TABLE statement.
• CHANGE TABLE: Not a recognized standard SQL command.

Analysis and Detail

1. ALTER TABLE is the correct answer, as it specifically allows changes to an existing table's structure without deleting it.
2. DELETE TABLE is generally misused terminology and doesn't exist in standard SQL.
3. MODIFY TABLE may seem correct but is not an isolated SQL command; it is integrated within the ALTER TABLE command.
4. CHANGE TABLE is also not a recognized command for altering table structures.

Verify and Summarize

The only SQL statement among the provided options that accurately and explicitly allows modification of an existing table's structure is ALTER TABLE.

Final Answer

ALTER TABLE