acnet_status.i2.v = db_modify(handle.g.v, request_buffer.i1a.r
This routine modifies data in relational databases using SQL.
Help with datatypes and creating tables is in intro_database.
Multiple SQL commands are allowed, no data return is expected.
If data is returned, db_select should be used instead whether
or not the caller is interested in the returned data.
handle database connection handle returned from
a previous call to db_open
request_buffer SQL statment text, NULL terminated string
rows_affected number of rows affected my modify statement
01. When a requested update finishes with a success return_code, this
indicates the SQL sent was executed without an error, not that the
SQL sent was the correct SQL to produce the desired results.
(ie. an update to a non-existent row is NOT a SQL error)
02. An update may have been successful even if an error was reported.
(ie. A timeout might occur after a request has begun being processed
by the database and therefore cannot be canceled.)
03. Because of 01 and 02, the user should re-read the appropriate data
after an update to assure the status of the data.
04. No locks are maintained in between calls, if a user needs
to make sure that data has not changed since the last time a table
was used, the user should re-read the data during an update
05. Sybase allows an unlimited number of commands in one request, this
is most useful for inserts.
06. Under all circumstances, combining multiple reads/updates in the
same request improves efficiency: e.g:
...select name from device where di in (1,2,3,4)... instead of
four separate requests.
...insert tbl values (1,2) insert tbl values (2,3) insert tbl
values (3,4)... instead of three separate requests.
This function returns ACNET status values as follows:
SQL_MOREROWS success, but available results were ignored
SQL_xxx database access failure
This function requires the following include files:
db_select, db_open, db_close, db_error, db_nextrow