close

Close and invalidate database and driver resource utilizer

Syntax

close(object)

Description

close(object) closes and invalidates the database and driver resource utilizer object to free up database and driver resources.

Examples

Close connection Object

Connect to a Microsoft® SQL Server® database and verify the database connection. Then, import data from the database into MATLAB®. Determine the highest unit cost among the retrieved products in the table. Close the database connection.

Create an ODBC database connection to a Microsoft® SQL Server® database with Windows® authentication. Specify a blank user name and password. The database contains the table productTable.

datasource = 'MS SQL Server Auth';
conn = database(datasource,'','');

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

conn.Message

ans =

     []

Select all data from productTable and sort it by the product number. data is a table containing the imported data that results from executing the SQL SELECT statement.

selectquery = 'SELECT * FROM productTable ORDER BY productNumber';
data = select(conn,selectquery);

Display the first three rows of data.

data(1:3,:)

ans =

  3×5 table

    productNumber    stockNumber    supplierNumber    unitCost    productDescription
    _____________    ___________    ______________    ________    __________________

          1          4.0035e+05          1001            14       'Building Blocks' 
          2          4.0031e+05          1002             9       'Painting Set'    
          3            4.01e+05          1009            17       'Slinky'          

Determine the highest unit cost in the table.

max(data.unitCost)

ans =

    24

Close the database connection.

close(conn)

Close DatabaseDatastore Object

Create a database connection using a JDBC driver. To create this connection, you must configure a JDBC data source. For more information, see the configureJDBCDataSource function. Then, create a DatabaseDatastore object and close it.

Create a database connection to the JDBC data source MSSQLServerJDBCAuth. This data source configures a JDBC driver to a Microsoft® SQL Server® database with Windows® authentication. Specify a blank user name and password.

datasource = "MSSQLServerJDBCAuth";
username = "";
password = "";
conn = database(datasource,username,password);

Create a DatabaseDatastore object using the database connection and an SQL query. This SQL query retrieves all data from the airlinesmall table.

sqlquery = "select * from airlinesmall";

dbds = databaseDatastore(conn,sqlquery);

Close the DatabaseDatastore object and the database connection.

close(dbds)

Input Arguments

object — Database and driver resource utilizer

connection object | DatabaseDatastore object

Database and driver resource utilizer, specified as one of the objects described in this table.

Object Argument Name	Object Name	Object Description	Object Creation Function
conn	connection	Create a connection between an installed database and MATLAB®. For details, see Connecting to Database.	database
dbds	DatabaseDatastore	Create a connection to a type of datastore for working with large data.	databaseDatastore

• connection objects and DatabaseDatastore objects remain open until you close them using the close function. Always close these objects when you finish using them.

• Executing close with a DatabaseDatastore object releases the MATLAB resources associated with the connection object.

Note

When you close the MATLAB session, MATLAB closes open DatabaseDatastore objects and connections. However, the database might not free up the connections. Consult your database administrator about the remaining connections.