How to query data from Oracle database?

To query data from an Oracle database, you can use SQL (Structured Query Language) statements. The most common command used to retrieve data is the SELECT statement.

Explanation:

• SELECT Statement: This command is used to select data from a database. The data returned is stored in a result table, called the result-set.
• Basic Syntax: SELECT column1, column2, ... FROM table_name WHERE condition;
• Example: If you have a table named "employees" and you want to retrieve all records where the department is 'Sales', the SQL query would look like this:

  SELECT * FROM employees WHERE department = 'Sales';
  

Steps to Query Data:

1. Connect to the Database: Use a tool like SQL*Plus, SQL Developer, or any other Oracle database client to connect to your Oracle database.
2. Write the SQL Query: Construct your SQL query based on what data you need.
3. Execute the Query: Run the query in your SQL client.
4. Review the Results: The results of your query will be displayed in the result-set.

Example with Specific Columns:
If you only need specific columns, such as employee ID and name, the query would be:

SELECT employee_id, first_name, last_name FROM employees WHERE department = 'Sales';

Using Tencent Cloud for Oracle Database:
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