[Oracle] First Trial of Oracle and first trial of oracle

[Oracle] First Trial of Oracle and first trial of oracle

I don't know how much you know about Oracle? Is it just to the extent that it can be used. In this case, I will follow my steps to learn more about Oracle and unveil the secrets of Oracle.

For the installation of Oracle, I don't want to talk about it here. In this tutorial, I will search for 10 Gb of 11 GB. At the beginning of the article, we will not start with the subject. After Oracle is installed, two users are automatically generated. Anyone familiar with Oracle knows that one is sys and the other is system. You may only know that these two are default database users and have high permissions. How many permissions does it have? You may not be able to say much. Let's just talk about these two special users.

First, sys is a super user with the highest permissions and the sysdba role. What is the role of sysdba? So far, let's talk about it. sysdba logs on as sysdba. When it comes to identity, Oracle has three identities: normal and normal, after authorized users, we often log on as normal; one is sysdba System Administrator; the other is sysoper system operator. Go back and continue to say that sys has the highest permission and the create database permission. The default password for this user is change_on_install. Haha, it's a little long. I will explain how to change the password later. Next we will introduce the system. We don't need to talk about it. We all know that it is a system administrator and has a high level of permissions. It has the role of sysoper. As mentioned above, it is the identity of a system operator, you do not have the create database permission. The default password is manager. The password is easy to remember. Next, we will introduce how to change the user password.

When will we change the password? At ordinary times, we always want to change our passwords, such as QQ and so on. Either the password is too long or we forget it. The same is true for users in Oracle. The default password of sys is as long as change_on_install. I guess you must have the urge to change the password. How can you change the password? Don't worry. Read it here.

1. Enter sqlplus/nolog in the command line without a user name to log on.

2. Connect conn/as sysdba to the local database

3. alter user *** (the user name you want to change, such as system) identified by *** (the password you want to change );

For example: alter user system identified by abc123; remember! This statement must be followed by a plus sign!

Now, let's end this blog. This is the simplest entry point for Oracle. Next, let's talk about how to use Navicat to connect to the Oracle database. See the next blog.