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isopen

Determine if database connection is open

Syntax

i = isopen(conn)

Description

example

i = isopen(conn) returns 1 if the database connection is open and 0 if the database connection is closed or invalid.

Examples

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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 =

     []

Determine if the database connection is open. The isopen function returns the numeric scalar 1, which means the database connection is open.

i = isopen(conn)
i =

     1

Select all the 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)

Determine if the database connection is closed. The isopen function returns the numeric scalar 0, which means the database connection is closed. If the database connection is invalid, the isopen function returns the same result.

i = isopen(conn)
i =

     0

Input Arguments

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Database connection, specified as a connection object created with the database function.

Introduced in R2015b