Anomalous commit/rollback behavior
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Please observe:
K>> get(conn, 'AutoCommit') % AutoCommit is Off
ans =
off
K>> curs = fetch(exec(conn, ['select * from RawValue r inner join CalculatedValue c '... 'on r.RawValueID=c.RawValueID where r.RealTimeFlagsID=-9998 and '... 'not r.SiteID like ''ADM%'''])) % Matlab just added the queried data to the database; note that (a lot of) data is being returned
curs =
Attributes: []
Data: {5271x58 cell}
DatabaseObject: [1x1 database]
RowLimit: 0
SQLQuery: [1x141 char]
Message: []
Type: 'Database Cursor Object'
ResultSet: [1x1 sun.jdbc.odbc.JdbcOdbcResultSet]
Cursor: [1x1 com.mathworks.toolbox.database.sqlExec]
Statement: [1x1 sun.jdbc.odbc.JdbcOdbcStatement]
Fetch: [1x1 com.mathworks.toolbox.database.fetchTheData]
K>> commit(conn) % Now I (ostensibly) commit it
K>> curs = fetch(exec(conn, ['select * from RawValue r inner join CalculatedValue c '... 'on r.RawValueID=c.RawValueID where r.RealTimeFlagsID=-9998 and '... 'not r.SiteID like ''ADM%'''])) % Yup, it's still there! :)
curs =
Attributes: []
Data: {5271x58 cell}
DatabaseObject: [1x1 database]
RowLimit: 0
SQLQuery: [1x141 char]
Message: []
Type: 'Database Cursor Object'
ResultSet: [1x1 sun.jdbc.odbc.JdbcOdbcResultSet]
Cursor: [1x1 com.mathworks.toolbox.database.sqlExec]
Statement: [1x1 sun.jdbc.odbc.JdbcOdbcStatement]
Fetch: [1x1 com.mathworks.toolbox.database.fetchTheData]
K>> rollback(conn) % My understanding is that this should now have no effect
K>> curs = fetch(exec(conn, ['select * from RawValue r inner join CalculatedValue c '... 'on r.RawValueID=c.RawValueID where r.RealTimeFlagsID=-9998 and '... 'not r.SiteID like ''ADM%'''])) *% But wait, there's less! :(*
curs =
Attributes: []
Data: {'No Data'}
DatabaseObject: [1x1 database]
RowLimit: 0
SQLQuery: [1x141 char]
Message: []
Type: 'Database Cursor Object'
ResultSet: [1x1 sun.jdbc.odbc.JdbcOdbcResultSet]
Cursor: [1x1 com.mathworks.toolbox.database.sqlExec]
Statement: [1x1 sun.jdbc.odbc.JdbcOdbcStatement]
Fetch: [1x1 com.mathworks.toolbox.database.fetchTheData]
Can someone please explain this result to me?
Thanks!
1 commentaire
Oleg Komarov
le 8 Août 2011
In the example you're using plain SELECT queries wich do not affect the content of a TABLE.
Réponses (0)
Voir également
Catégories
En savoir plus sur Database Toolbox dans Help Center et File Exchange
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!