isopen
Syntax
Description
Examples
Determine If Database Connection Is Open
Connect to a MySQL® database using the MySQL native interface and verify the database connection. Then, import data from the database into MATLAB® using the database table productTable
. Determine the highest unit cost among the retrieved products in the table. Close the database connection and ensure that the connection is closed.
Create a MySQL native interface database connection using a data source, user name, and password. The MySQL database contains the table productTable
.
datasource = "MySQLNative"; username = "root"; password = "matlab"; conn = mysql(datasource,username,password);
Determine if the database connection is open. The isopen
function returns the logical 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)
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 logical 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
Input Arguments
conn
— MySQL native interface database connection
connection
object
MySQL native interface database connection, specified as a connection
object. Starting in R2024a, it is recommended that you use setSecret
and getSecret
to store and retrieve your credentials for databases that require authentication. For
more details, refer to this
example.
Version History
Introduced in R2020b
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