rollback

Undo changes to PostgreSQL database

Since R2020b

Syntax

rollback(conn)

Description

rollback(conn) reverses changes made to a database using functions such as sqlwrite. The rollback function reverses all changes made since the last COMMIT or ROLLBACK operation. To use this function, you must set the AutoCommit property of the connection object to off.

Examples

Reverse Changes Made to PostgreSQL Database

Use a PostgreSQL native interface database connection to insert product data from MATLAB® into a new table in a PostgreSQL database. Then, reverse the changes made to the database.

Create a PostgreSQL native interface database connection to a PostgreSQL database using the data source name, user name, and password. The database contains the tables productTable and suppliers.

datasource = "PostgreSQLDataSource";
username = "dbdev";
password = "matlab";
conn = postgresql(datasource,username,password);

Allow manual committing of changes to the database by setting the AutoCommit property to off.

conn.AutoCommit = "off";

Create a MATLAB table that contains data for two products. The data is stored in the productTable and suppliers tables.

data = table([30;40],[500000;600000],[1000;2000],[25;30], ...
    ["Rubik's Cube";"Doll House"],'VariableNames',["productNumber" ...
    "stockNumber" "supplierNumber" "unitCost" "productDescription"]);

Insert the product data into a new table named toytable.

tablename = "toytable";
sqlwrite(conn,tablename,data)

Import the contents of the database table into MATLAB and display the rows. The results contain two rows for the inserted products.

rows = sqlread(conn,tablename)

rows=2×5 table
    productnumber    stocknumber    suppliernumber    unitcost    productdescription
    _____________    ___________    ______________    ________    __________________

         30             5e+05            1000            25         "Rubik's Cube"  
         40             6e+05            2000            30         "Doll House"    

Reverse the changes made to the database.

rollback(conn)

Search for the table. The table no longer exists.

data = sqlfind(conn,tablename)

data =

  0×5 empty table

Close the database connection.

close(conn)

Input Arguments

conn — PostgreSQL native interface database connection

connection object

PostgreSQL native interface database connection, specified as a connection object.

Version History

Introduced in R2020b