isopen

Connect to an SQLite 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 the SQLite connection conn to the existing SQLite database file tutorial.db. The database file contains the table productTable. The SQLite connection is an sqlite object.

dbfile = "tutorial.db";
conn = sqlite(dbfile);

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 = logical
   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.

sqlquery = "SELECT * FROM productTable ORDER BY productNumber";
data = fetch(conn,sqlquery);

Display the first three rows of data.

head(data,3)

    productNumber    stockNumber    supplierNumber    unitCost    productDescription
    _____________    ___________    ______________    ________    __________________

          1            400345            1001            14       "Building Blocks" 
          2            400314            1002             9       "Painting Set"    
          3            400999            1009            17       "Slinky"          

Determine the highest unit cost in the table.

max(data.unitCost)

ans = int64

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 = logical
   0