MATLAB Examples

# Insert Data into Database Table

This example shows how to import data from a database into MATLAB®, perform calculations on the data, and export the results to a database table.

The example assumes that you are connecting to a Microsoft® Access™ database that contains tables named salesvolume and yearlysales. Also, the example assumes that you start MATLAB as an administrator. The salesvolume table contains the column names for each month. The yearlysales table contains the column names month and salestotal.

## Connect to Database

Create a database connection to the Microsoft Access database. For example, this code assumes that you are connecting to a data source named dbdemo with a blank user name and password.

```conn = database('dbdemo','',''); ```

Check the database connection. If the Message property is empty, then the connection is successful.

```conn.Message ```
```ans = [] ```

## Calculate Sum of Sales Volume for One Month

Import sales volume data for the month of March using the database connection. The salesvolume database table contains sales volume data.

```tablename = 'salesvolume'; data = sqlread(conn,tablename); ```

Display the first three rows of sales volume data. The fourth variable contains the data for the month of March.

```head(data(:,4),3) ```
```ans = 3×1 table march _____ 981 1414 890 ```

Calculate the sum of the March sales. Assign the result to the MATLAB workspace variable total and display the result.

```total = sum(data.march) ```
```total = 14606 ```

## Insert Total Sales for One Month into Database

Retrieve the name of the month from the sales volume data.

```month = data.Properties.VariableNames(4); ```

Define the names of the columns for the data to insert as a cell array of character vectors.

```colnames = {'month' 'salestotal'}; ```

Create a MATLAB table that stores the data to export.

```results = table(month,total,'VariableNames',colnames); ```

Determine the status of the AutoCommit database flag. This status determines whether or not the insert action can be undone.

```conn.AutoCommit ```
```ans = 'on' ```

The AutoCommit flag is set to on. The database commits the exported data automatically to the database, and this action cannot be undone.

Insert the sum of sales for the month of March into the yearlysales table.

```tablename = 'yearlysales'; sqlwrite(conn,tablename,results) ```

Import the data from the yearlysales table. This data contains the calculated result.

```data = sqlread(conn,tablename) ```
```data = 1×3 table month salestotal revenue _______ __________ _______ 'march' 14606 0 ```

## Close Database Connection

```close(conn) ```