Let's talk about the methods and steps for importing data into Oracle

Oracle database is currently one of the most popular relational databases in the world and has a wide range of applications. In the process of using Oracle database, data import is a very important link. This article will briefly introduce the methods and steps for importing data into Oracle.

1. Prerequisite preparations for Oracle data import

Before importing Oracle data, you need to make some prerequisite preparations, which mainly include the following steps:

1. Prepare The data source can be a text file, Excel file, Access file, etc.

2. Create the target table structure to import data, including table name, field name, field type, constraints, etc.

3. Check Oracle's character set to ensure that the data character set in the data source is consistent with the Oracle character set to avoid garbled characters when importing data.

2. Methods and steps for importing data into Oracle

When importing Oracle data, you can use a variety of methods. Below we will introduce their steps one by one:

Method 1: Use SQL*Loader to import data

SQL*Loader is a tool officially provided by Oracle for fast and efficient batch loading of data. It supports multiple operating systems and is one of Oracle's preferred tools for importing data.

1. Create a data file that includes the field values ​​of the data. Files can be in text or binary format.

2. Create a control file, specify the target table to import data, and details such as the format and location of each field in the data file. You can use a text editor to create a control file manually, or you can use the control file generator provided by Oracle to generate a control file.

3. Use the SQL*Loader tool to load data. The command is as follows:

sqlldr username/password control=controlfile.ctl

Note: If the data file and the control file are in the same In a directory, the path can be omitted.

Method 2: Use the Oracle Import Wizard

The Oracle Import Wizard is a graphical interface tool that is very convenient and easy to use, suitable for beginners and lightweight data import scenarios.

1. Open the Oracle Import Wizard and select the file type to import data (text file, Excel file, etc.).

2. Select the target table to import data into, and specify the table name, field name and other information.

3. Specify the path to the data source file and click Next.

4. Select the data attributes to be imported, including delimiters, text qualifiers, etc.

5. Set import rules according to the actual situation, such as whether to overwrite existing data, whether to skip duplicate data, etc.

6. After confirming that the import parameters are correct, start importing data.

Method 3: Use an external table to import data

An external table is a special table in Oracle. It uses the data file as part of the table and can be queried, inserted, etc. like a normal table. operate. The steps to import data using an external table are as follows:

1. Create an external table in the Oracle database, including table name, field name and other information.

2. Create a data file that includes the field values ​​of the data. Files can be in text or binary format.

3. Bind the path of the data file to the external table, use the following statement:

ALTER TABLE external_tab_name LOCATION ('/path/to/datafile');

4. Query data from external tables, Oracle will automatically load the data and perform format conversion and other processing.

3. Summary

This article introduces three methods for Oracle to import data, including SQL*Loader, Oracle Import Wizard and external tables. Different scenarios and needs allow you to choose different methods for data import. Before importing data, some preparatory work needs to be done to ensure that the data import can proceed smoothly.

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