ResultType
|
Previous Top Next |
· | parse your sql (SQL property) replacing macros
|
· | insert any master-detail and filter conditions giving a Final SQL
|
· | sent your Final SQL query to the mysql server,
|
· | the mysql server will execute this query fetch the records (result set) for you
|
· | and start sending the records to the dataset one at a time.
|
· | parse your sql (SQL property) replacing macros
|
· | insert any master-detail and filter conditions giving a Final SQL
|
· | sent your Final SQL query to the mysql server,
|
· | the mysql server will execute this query fetch the records (result set) for you
|
· | and start sending the records to the dataset one at a time when prompted
|
· | parse your sql (SQL property) replacing macros
|
· | insert any master-detail and filter conditions giving a Final SQL
|
· | sent your Final SQL query to the mysql server,
|
· | the mysql server will execute this query fetch the records (result set) for you
|
· | and start sending the records to the dataset one at a time when prompted
|
· | You don't have to wait for large result sets or result sets with large blob fields to completely populate your dataset
|
· | Your connection to your MySQL server must be live until the last record was fetched, if it was to disconnect your result will contain only records fetched until that moment.
|
· | Your RecordCount will always equal = Records actually fetched + 1
|
· | No "show columns from ..." statements are executed, thus you columns will not show the default values you setup in your database tables on the MySQL server when you insert a new record. Use OnNewRecord to correct this problem.
|
· | ShareConnection property = True and rtIncremental are mutually exclusive, thus this dataset must have its own thread to the mysql server as to not block your TMySQLServer or other TMySQLDatasets using the TMySQLServer of this dataset while this dataset has not finished collecting all the records.
|
· | Another disadvantage is that if you update a record while all the records have not been fetched your dataset will have to stop the fetching, sent the update and re-fetch all the records up to the point where you are. You can prevent this though using a combination of rtIncremental and CachedUpdates.
|
1. | Firstly if you have CachedUpdates enabled, the updating sql is just added to the cached statements and thus executed later, i.e. with the close or refresh of this dataset. Your record you are updating is in memory already and thus the changes will reflect immediately to the end-user.
|
2. | If caching is not enabled, but ThreadedUpdates is, then the dataset will sent the updating sql to the server using another thread and thus connection.
|
3. | If neither caching nor threadedupdates are enabled, then the dataset will load the rest of the dataset's records in the background, send the updating SQL and then refetch all the data upto the record which you just updated.
|