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Editor to share with you to achieve the application of mysql add, delete, change and search function of the method, I believe that most people do not know much, so share this article for your reference, I hope you will learn a lot after reading this article, let's go to understand it!

1. Preface

The addition, modification, deletion and query of data are the most commonly used functions in application software systems. As a software developer, it is very important to realize the above functions efficiently and to ensure the correctness, standardization and validity of the system data.

Combined with the addition, deletion, change and search function completed in the project practice, this paper analyzes and summarizes the development process and methods to achieve the add, delete, change and search function, in order to better complete the development of similar functions in the follow-up development work.

two。 Development process and method

Add featur

The added function is mainly to save the data items entered by the user in the page to the corresponding data table field in the data table.

The following steps can be used for analysis and implementation:

According to the business needs, what data items do users need to enter on the analysis page?

What data items need to be entered?

What is the entry method of each data item (text box entry, drop-down list entry, checkbox entry, radio entry) and verification rules (non-null check, field type, field length, field format)?

Enter the corresponding relationship between the data item and the data table field (which data table, which data field,)

Each data item on the page corresponds to which field of which data table?

Does the data item value entered on the page need to be converted to the value of the database field? (for example, whether the user is entered in the page and converted into database fields 1 and 0)

When saving data in the background, follow these steps:

If the data verification is incorrect, indicate which data items are not in the correct format and how to fill them in the correct format.

If the save fails, the reason for the failure will be prompted to the user, so that the user can modify it and save it again.

If the save is successful, the result of the successful operation will be fed back to the user.

If you save an exception, you will be prompted to save an exception. Please try again.

If the VO data of the page corresponds to only one data table, it can be saved directly to a data table.

If the VO data of the page needs to be saved to multiple data tables in the database, we need to use the transaction management mechanism to control the integrity of the data preservation operation to prevent some tables from being saved successfully and some tables from failing.

If duplicate records already exist, the duplicate information will be fed back to the user.

If there are no duplicate records, perform the following save steps.

First, you need to receive the data items entered on the page, then verify the validity and validity of the data items (type, length), and set the

Then, combined with the uniqueness rule of the data, it is determined whether there are duplicate data records.

Next, realize the conversion between the page VO data items and the persistent object PO: convert the VO data items entered by the user on the page into database entity objects, and call the corresponding primary key generation rules to generate the primary key fields and other field values of the database entity objects that are not related to business but need to be saved to the database; perform the following save operations:

Finally, the result of the save operation is fed back to the user:

Delete function

The deletion function is mainly to delete the data selected by the user from the database, so that the data can not be seen on the page.

It can be analyzed and implemented in the following ways:

Analyze the implementation of deletion:

Use hard deletion (delete the data directly from the database) or soft delete (identify the data has been deleted by identification bits)

Cascading data that is hierarchically deleted:

Whether there is record deletion for the deleted data on the page: delete a piece of data in one data table and delete the data record related to that record in another data table at the same time.

Analyze the operation of the deletion:

Delete based on which data item of the data record

Only one piece of data can be deleted at a time.

Multiple pieces of data can be deleted at a time.

The implementation method of the delete operation:

The backend acquires the primary key value of the data record to be deleted and performs the deletion operation; if there is a cascade deletion, you need to delete the data record related to that record in the relevant data table after deleting the data record of the current table to ensure that there is no invalid redundant data in the database.

In the case of batch deletion, if one of the data deletions is wrong, write the record to the prompt and continue to delete the subsequent data records.

Feedback the processing result of the delete operation to the operation user:

If the deletion fails, report back to the reason why the deletion failed

If the exception is deleted, the cause of the exception is reported and the user is prompted to try again.

If the deletion is successful, the message of the successful operation will be given to the user.

Hide the primary key of the data record and display it on the page when viewing the data

When selecting data, save the primary key corresponding to the selected data

When the user clicks the delete button, the user is first prompted to confirm the deletion. If the user chooses to confirm the deletion, perform the following processing steps:

After the deletion is successful, you need to refresh the display data on the page and show the result of the deletion (the successfully deleted data is no longer displayed on the page) to the user.

Modify function

The modification function is mainly to re-edit the existing data items in the database and save the modified data to the database.

Query function

In an overview, the development methods of the Web layer are as follows:

Write the page VO: analyze which data items need to be submitted and which result data items need to be returned in the Web display layer; encapsulate the request data items and result data items into the page VO. When coding the implementation, the page VO class is a normal Bean class, defining data items and providing set and get methods.

Write the control layer Action: define the page VO object; use the page VO object to receive the request data submitted by the Web display layer; convert the request data submitted by the VO into a data transmission object and transmit it to the Service layer for use; receive the processing result returned by the service layer; convert the data transmission object returned by the processing result into the result data item of the VO.

Write an Action configuration file:

Establish the corresponding relationship between the display layer request and the control layer request: establish the corresponding relationship between the page request and the Action by configuring the Action information in the configuration file of the Action.

Write a display layer page:

Use the page VO to receive the user's request data: set the form name in the page to be the same as the property name of the page VO to ensure that the page VO can receive the request data.

Set the Action address for the request: for the page button that submitted the request, set the requested address to the Action address to ensure that the request can be submitted to the corresponding one.

Receive the returned processing result: receive the processing result returned by the request, and carry on the corresponding processing according to the processing result.

The above are all the contents of the method of applying the function of adding, deleting, changing and searching mysql. Thank you for your reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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