How to query the serial number in oracle

Oracle query serial number method: 1. Connect to the Oracle database and use SQL Plus tools or other tools that support connecting to the Oracle database; 2. Write a query statement to query the current value of the serial number and query the specified sequence. To query the current value of the sequence number, query the next value of the specified sequence; 3. Execute the query statement. After writing the query statement, you can execute it in the connected Oracle database. Executing the query statement will return the corresponding results. .

The operating environment of this tutorial: Windows 10 system, Oracle version 19c, DELL G3 computer.

Oracle is a very popular relational database management system used to store and manage large amounts of data. In Oracle database, a sequence is an object that provides unique increasing values ​​to a table. In this article, we will introduce how to query the Oracle serial number.

To query the Oracle serial number, you can use SQL statements. The specific steps are as follows:

Step 1: Connect to the Oracle database

To query the Oracle serial number, you first need to connect to the corresponding Oracle database. This can be achieved using SQL Plus tools or other tools that support connecting to Oracle databases.

Step 2: Write a query statement

After connecting to the Oracle database, you can write a query statement to query the serial number. The following are some examples of commonly used query sequence number statements:

1. Query the current value of the sequence number:

SELECT sequence_name, last_number FROM user_sequences;

This query statement will Returns the names of all sequences under the current user and the most recently generated sequence number.

2. Query the current value of the specified sequence:

SELECT last_number FROM user_sequences WHERE sequence_name = 'sequence_name';

In the above query, replace 'sequence_name' with the actual sequence name to query the current value of a specific sequence.

3. Query the next value of the sequence number:

SELECT sequence_name, last_number increment_by AS next_number

FROM user_sequences;

This query statement will return the current The names of all sequences under the user and the next value of the sequence.

4. Query the next value of the specified sequence:

SELECT last_number increment_by AS next_number

FROM user_sequences WHERE sequence_name = 'sequence_name';

In this In the query, replace 'sequence_name' with the actual sequence name to query for the next value of a specific sequence.

Step 3: Execute the query statement

After writing the query statement, you can execute it in the connected Oracle database. Executing the query statement will return the corresponding results.

Supplementary instructions:

The query statement in the above example queries the serial number by accessing the user's sequence object. This means it will return the sequence to which the current user has access. If you want to query the sequences of other users, you can use a user with corresponding permissions to connect to the Oracle database, then modify 'user_sequences' in the query statement to 'all_sequences', and modify the permissions accordingly.

Summary:

Querying the Oracle serial number is achieved by writing query statements. By using SQL statements, you can query the current value and next value of the serial number. By connecting to the corresponding Oracle database and running the query statement, you can obtain information about the serial number. This is very helpful in developing and maintaining sequences in Oracle database .

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