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ormupdate

Update database tables using object relational mapping

Since R2023b

    Description

    example

    ormupdate(conn,ormObject) updates a database table with the properties of the mappable objects in ormObject based on a connection object conn. This method identifies which row of the database each object represents, and then updates each one using the current object properties. For more information on mappable objects, see database.orm.mixin.Mappable.

    Examples

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    This example depends on the Product class that maps to a database table. This class contains several properties that map to the database, as well as some methods that alter those properties.

    classdef (TableName = "products") Product < database.orm.mixin.Mappable
    
        properties(PrimaryKey,ColumnName = "ProductNumber")
            ID int32
        end
        
        properties
            Name string
            Description string
            Quantity int32
        end
    
        properties(ColumnName = "UnitCost")
            CostPerItem double
        end
    
        properties(ColumnName = "Manufacturer")
            Supplier string
        end
    
        properties(ColumnType = "date")
            InventoryDate datetime
        end
    
        methods
            function obj = Product(id,name,description,supplier,cost,quantity,inventoryDate)
                if nargin ~= 0
                    inputElements = numel(id);
                    if numel(name) ~= inputElements || ...
                            numel(description) ~= inputElements || ...
                            numel(supplier) ~= inputElements || ...
                            numel(cost) ~= inputElements || ...
                            numel(quantity) ~= inputElements || ...
                            numel(inventoryDate) ~= inputElements
                        error('All inputs must have the same number of elements')
                    end
        
                    %Preallocate by creating the last object first
                    obj(inputElements).ID = id(inputElements);
                    obj(inputElements).Name = name(inputElements);
                    obj(inputElements).Description = description(inputElements);
                    obj(inputElements).Supplier = supplier(inputElements);
                    obj(inputElements).CostPerItem = cost(inputElements);
                    obj(inputElements).Quantity = quantity(inputElements);
                    obj(inputElements).InventoryDate = inventoryDate(inputElements);
    
                    for n = 1:inputElements-1
                        %Fill in the rest of the objects
                        obj(n).ID = id(n);
                        obj(n).Name = name(n);
                        obj(n).Description = description(n);
                        obj(n).Supplier = supplier(n);
                        obj(n).CostPerItem = cost(n);
                        obj(n).Quantity = quantity(n);
                        obj(n).InventoryDate = inventoryDate(n);
                    end
                end
            end
            function obj = adjustPrice(obj,amount)
                arguments
                    obj (1,1) Product
                    amount (1,1) {mustBeNumeric}
                end
               obj.CostPerItem = obj.CostPerItem + amount; 
            end
    
            function obj = shipProduct(obj,amount)
                arguments
                    obj (1,1) Product
                    amount (1,1) {mustBePositive,mustBeInteger}
                end
    
                obj.Quantity = obj.Quantity - amount;
            end
    
            function obj = recieveProduct(obj,amount)
                arguments
                    obj (1,1) Product
                    amount (1,1) {mustBePositive,mustBeInteger}
                end
    
                obj.Quantity = obj.Quantity + amount;
                obj.InventoryDate = datetime('today');
            end
    
        end
    
    end
    

    First, create an sqlite database file that does not require a connection to a live database.

    filename = "orm_demo.db";
    if exist(filename,"file")
        conn = sqlite(filename);
    else
        conn = sqlite(filename,"create");
    end
    
    %Remove the table if it already exists to maintain consistency
    execute(conn,"DROP TABLE IF EXISTS products");

    Use the orm2sql function to display the database column information based on the class defined in Product.m.

    orm2sql(conn,"Product")
    ans = 
        "CREATE TABLE products
         (ProductNumber double, 
         Name text, 
         Description text, 
         Quantity double, 
         UnitCost double, 
         Manufacturer text, 
         InventoryDate date, 
         PRIMARY KEY (ProductNumber))"
    
    

    Create a Product object to create and populate a table.

    toy = Product(1,"Toy1","Descr1","CompanyA",24.99,0,datetime(2023,1,1))
    toy = 
      Product with properties:
    
                   ID: 1
                 Name: "Toy1"
          Description: "Descr1"
             Quantity: 0
          CostPerItem: 24.9900
             Supplier: "CompanyA"
        InventoryDate: 01-Jan-2023
    
    

    Use the ormwrite function to populate the database with the data from toy, and use the sqlread function to read the table and verify the results.

    ormwrite(conn,toy);
    sqlread(conn,"products")
    ans=1×7 table
        ProductNumber     Name     Description    Quantity    UnitCost    Manufacturer           InventoryDate        
        _____________    ______    ___________    ________    ________    ____________    ____________________________
    
              1          "Toy1"     "Descr1"         0         24.99       "CompanyA"     "2023-01-01 00:00:00.000000"
    
    

    Use the receiveProduct method of the Product class to increase the inventory of Toy1.

    toy = recieveProduct(toy,500)
    toy = 
      Product with properties:
    
                   ID: 1
                 Name: "Toy1"
          Description: "Descr1"
             Quantity: 500
          CostPerItem: 24.9900
             Supplier: "CompanyA"
        InventoryDate: 28-Jul-2023
    
    

    Use the ormupdate method to push the changes made in MATLAB® to the database. Then, use the fetch function to verify that Quantity and InventoryDate are updated in the database.

    ormupdate(conn,toy);
    fetch(conn,"SELECT * FROM products WHERE Name = 'Toy1'")
    ans=1×7 table
        ProductNumber     Name     Description    Quantity    UnitCost    Manufacturer           InventoryDate        
        _____________    ______    ___________    ________    ________    ____________    ____________________________
    
              1          "Toy1"     "Descr1"        500        24.99       "CompanyA"     "2023-07-28 00:00:00.000000"
    
    
    clear ans toy
    close(conn)

    Input Arguments

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    Database connection, specified as a connection object created by any of the following:

    Mappable object, specified as a scalar or vector. For more information on mappable objects, see database.orm.mixin.Mappable.

    Version History

    Introduced in R2023b