The am_update purpose function

The database server calls am_update to process an UPDATE statement.

Syntax

mi_integer am_update(MI_AM_TABLE_DESC *tableDesc, 
   MI_ROW *row, mi_integer rowid);

tableDesc: Points to the table descriptor.
row: Points to the row structure that contains the updated values.
rowid: Indicates where to write the updated values.

Usage

The am_update function modifies the contents of an existing row.

If the access method needs to move the updated row, am_update can take the following actions:

Deletes the old row
Adjusts the data format in row to conform to the source data
Stores the updated source-data record
Stores the updated row identifier

Important: The database server does not call am_update unless both the am_rowids and am_readwrite purpose flags are set.

Important: If the access method does not supply am_update, but an SQL statement requires it, the database server raises an error. For more information about how to handle this error, see Supply error messages and a user guide.

For more information, see the purpose flags am_rowids and am_readwrite in Settings purpose functions, flags, and values.

Return values

MI_OK: Indicates success.
MI_ERROR: Indicates failure.