reset
Reset DatabaseDatastore
to initial
state
Syntax
Description
Examples
Create a database connection using a JDBC driver. To create this connection, you must configure a JDBC data source. For more information, see the
function. Then, create a configureJDBCDataSource
DatabaseDatastore
object, read the data stored in the object, and reset the object to its original state.
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. Specify reading a maximum of 10 records from the executed SQL query.
sqlquery = 'select * from airlinesmall'; dbds = databaseDatastore(conn,sqlquery,'ReadSize',10);
Read data from the start of the data set.
read(dbds)
ans = 10×29 table Year Month DayofMonth DayOfWeek DepTime CRSDepTime ArrTime CRSArrTime UniqueCarrier FlightNum TailNum ActualElapsedTime CRSElapsedTime AirTime ArrDelay DepDelay Origin Dest Distance TaxiIn TaxiOut Cancelled CancellationCode Diverted CarrierDelay WeatherDelay NASDelay SecurityDelay LateAircraftDelay ____ _____ __________ _________ _______ __________ _______ __________ _____________ _________ _______ _________________ ______________ _______ ________ ________ ______ _____ ________ ______ _______ _________ ________________ ________ ____________ ____________ ________ _____________ _________________ 1987 10 30 5 1329 1329 1434 1436 'US' 683 'NA' 65 67 'NA' -2 0 'LGA' 'BUF' 292 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 7 6 1316 1315 1713 1647 'TW' 810 'NA' 177 152 'NA' 26 1 'STL' 'BOS' 1046 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 28 6 815 815 1015 1015 'WN' 441 'NA' 120 120 'NA' 0 0 'BNA' 'HOU' 670 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 2 1 700 700 800 800 'NW' 790 'NA' 60 60 'NA' 0 0 'BTR' 'MEM' 319 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 14 6 840 840 1127 1120 'CO' 733 'NA' 167 160 'NA' 7 0 'EWR' 'MCO' 938 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 1 7 1625 1625 1823 1758 'DL' 957 'NA' 118 93 'NA' 25 0 'EWR' 'CVG' 569 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 26 4 1314 1315 1538 1542 'AA' 398 'NA' 84 87 'NA' -4 -1 'BNA' 'RDU' 443 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 10 28 3 1140 1140 1212 1215 'US' 262 'NA' 32 35 'NA' -3 0 'CLE' 'PIT' 105 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 10 9 5 1155 1155 1250 1300 'US' 282 'NA' 55 65 'NA' -10 0 'ROC' 'LGA' 254 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 10 22 4 715 715 807 803 'US' 304 'NA' 52 48 'NA' 4 0 'DTW' 'PIT' 201 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA'
read
returns the first 10 records in the data set.
Reset the DatabaseDatastore
object to its original state, where no data has been read from it. Resetting allows you to reread from the same DatabaseDatastore
object.
reset(dbds)
Read data from the start of the data set.
read(dbds)
ans = 10×29 table Year Month DayofMonth DayOfWeek DepTime CRSDepTime ArrTime CRSArrTime UniqueCarrier FlightNum TailNum ActualElapsedTime CRSElapsedTime AirTime ArrDelay DepDelay Origin Dest Distance TaxiIn TaxiOut Cancelled CancellationCode Diverted CarrierDelay WeatherDelay NASDelay SecurityDelay LateAircraftDelay ____ _____ __________ _________ _______ __________ _______ __________ _____________ _________ _______ _________________ ______________ _______ ________ ________ ______ _____ ________ ______ _______ _________ ________________ ________ ____________ ____________ ________ _____________ _________________ 1987 10 30 5 1329 1329 1434 1436 'US' 683 'NA' 65 67 'NA' -2 0 'LGA' 'BUF' 292 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 7 6 1316 1315 1713 1647 'TW' 810 'NA' 177 152 'NA' 26 1 'STL' 'BOS' 1046 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 28 6 815 815 1015 1015 'WN' 441 'NA' 120 120 'NA' 0 0 'BNA' 'HOU' 670 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 2 1 700 700 800 800 'NW' 790 'NA' 60 60 'NA' 0 0 'BTR' 'MEM' 319 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 14 6 840 840 1127 1120 'CO' 733 'NA' 167 160 'NA' 7 0 'EWR' 'MCO' 938 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 1 7 1625 1625 1823 1758 'DL' 957 'NA' 118 93 'NA' 25 0 'EWR' 'CVG' 569 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 11 26 4 1314 1315 1538 1542 'AA' 398 'NA' 84 87 'NA' -4 -1 'BNA' 'RDU' 443 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 10 28 3 1140 1140 1212 1215 'US' 262 'NA' 32 35 'NA' -3 0 'CLE' 'PIT' 105 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 10 9 5 1155 1155 1250 1300 'US' 282 'NA' 55 65 'NA' -10 0 'ROC' 'LGA' 254 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA' 1987 10 22 4 715 715 807 803 'US' 304 'NA' 52 48 'NA' 4 0 'DTW' 'PIT' 201 'NA' 'NA' 0 'NA' 0 'NA' 'NA' 'NA' 'NA' 'NA'
read
again returns the first 10 records in the data set.
Close the DatabaseDatastore
object and the database connection.
close(dbds)
Input Arguments
Datastore containing data in a database, specified as a DatabaseDatastore
object
created using the databaseDatastore
function.
Version History
Introduced in R2014b
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