Let's talk about how to execute sql statements in oracle

Oracle is a software based on a relational database management system, and its core is the SQL language. SQL is a standard language for working with relational databases. It can be used to query, insert, delete and update data. This article will introduce you to how Oracle executes SQL.

1. Open SQL*Plus

To execute SQL statements, you first need to open the SQLPlus tool. SQLPlus is an interactive command line tool provided by Oracle that allows users to execute SQL statements. In Windows operating systems, a shortcut to SQL*Plus can be found in the Start menu. On Linux or UNIX systems, you can open a terminal and enter the sqlplus command.

2. Log in to the database

After installing Oracle, you need to log in to the database using your user name and password to execute SQL statements. In SQLPlus, you can use the CONNECT command to log in to the database. For example, if the user name is scott and the password is tiger, you can enter the following command in SQLPlus:

CONNECT scott/tiger

If you log in successfully, SQL*Plus will display the following information:

Connected.

3. Enter SQL statements

Once you successfully log in, you can start entering SQL statements. SQL statements can be used to query tables, insert data, update data or delete data, etc. For example, we can enter the following SQL statement to query the information of all students:

SELECT * FROM Students;

This SQL statement will query all records in the table named Students and then return all their columns. In SQL*Plus, every SQL statement must end with ";"

4. Execute SQL statement

After entering the SQL statement, you can execute the statement by pressing the Enter key. If the SQL statement is correct, Oracle will execute it and return the query results. For example, if you execute the above SQL statement, SQL*Plus will print out the information of all students:

STUDENTID    NAME          AGE  GENDER
----------- -------------- ---- ------
001         Tom           20   Male
002         Lily          19   Female
003         Jack          22   Male
004         Lucy          21   Female
...

5. Exit SQL*Plus

After all SQL statements are executed , you need to exit the SQLPlus tool. You can exit using the EXIT or QUIT command. For example, you can enter the following command to exit SQLPlus:

EXIT;

Or:

QUIT;

Summary

Executing SQL statements in Oracle is very simple, just use SQL *Plus This tool logs in to the database and enters the SQL statement that needs to be executed. If the SQL statement is correct, Oracle will execute it and return the query results. Using SQL language, you can easily manipulate data in Oracle database to meet various business needs.

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