Oracle checks which tables are in the database

There are four ways to query tables in Oracle database: Using SQL query: Use SELECT * FROM

syntax. Using JDBC: Use Statement and ResultSet objects. Using PL/SQL: Use CURSOR and FOR loops. Use Oracle tools: such as SQL*Plus, Toad, and Data Modeler.

How to query the tables in the Oracle database

To query the tables in the Oracle database, you can use the following method:

1. Query using SQL

This is the most common method of querying tables in Oracle database. Use the following syntax:

SELECT * FROM <table_name>

For example, to query all records in the customers table, you can use the following query:

SELECT * FROM customers

2. Using JDBC

JDBC (Java Database Connectivity) is an API that allows Java programs to interact with databases. Query the table using the following code:

Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM customers");

3. Using PL/SQL

PL/SQL is Oracle's procedural language. Use the following code to query the table:

DECLARE
  CURSOR c_customers IS
    SELECT * FROM customers;
BEGIN
  FOR r IN c_customers LOOP
    DBMS_OUTPUT.PUT_LINE(r.customer_id);
  END LOOP;
END;

4. Using Oracle tools

Oracle provides a variety of tools to query the table, including:

• SQL*Plus: Interactive SQL query tool
• Toad: Third-party database management tool
• Data Modeler: Tools for designing and managing database models

Which method you choose depends on your specific needs and preferences.

The above is the detailed content of Oracle checks which tables are in the database. For more information, please follow other related articles on the PHP Chinese website!