Which data manipulation command is used to combines the records from one or more tables?SELECTPROJECTJOINPRODUCT

Step 1: Break Down the Problem

To answer this question, we need to identify which command among the given options is used to combine records from one or more tables in database management systems.

Step 2: Relevant Concepts

In SQL (Structured Query Language), a specific command is used to combine records from multiple tables. The key commands relevant to this question are:

• SELECT: Used to query records from a database.
• PROJECT: Typically refers to selecting specific columns in a result set (not a standard SQL command).
• JOIN: A command used to combine rows from two or more tables based on a related column.
• PRODUCT: Refers to the Cartesian product of tables, which is not a direct manipulation command as understood in the context of combining records meaningfully.

Step 3: Analysis and Detail

Among the choices provided:

1. SELECT is primarily used for querying data.
2. PROJECT is not a standard SQL command used to manipulate tables.
3. JOIN specifically denotes the action of combining rows from two or more tables based on a related column. This is the correct choice for combining records.
4. PRODUCT refers to generating all possible combinations of rows from two tables (Cartesian product), which is not typically used for meaningful data combination as understood in most contexts.

Step 4: Verify and Summarize

After analyzing the definitions and purposes of each command listed, it is clear that the command JOIN is specifically designed for combining records from one or more tables.

Final Answer

The correct command used to combine the records from one or more tables is JOIN.