The following table describes the things to consider when using the UPDATE statement.
| Topic | Usage Notes |
|---|---|
| OR Construct | The OR construct cannot be used in an UPDATE statement. To accomplish the result normally achieved with the OR construct, use two separate UPDATE statements and use the APPLY clause of the IMPORT command to apply them conditionally. |
| Referencing Field Names | Make references to fields of the input data records for the expr and WHERE conditional as follows::fieldname where fieldname is defined by a FIELD or TABLE command of the layout referenced by an IMPORT command using this UPDATE statement. For the WHERE condition clause, the equality values for all the columns of the primary index must be explicitly specified. |
| Required Privileges | To use the UPDATE statement, the UPDATE privilege on the tname table or view is required. |
| Specifying Multiple UPI Columns in an Import Task | If multiple UPI columns in an import task are specified, specify them all in the WHERE clause of the UPDATE statement. In this case, the WHERE clause is fully qualified, thereby allowing Teradata MultiLoad to optimize the processing. |
| Update Object Restrictions | If the object of the UPDATE statement is a view, it must not specify a join. Teradata MultiLoad operates only on single tables, so UPDATE statements must not contain any joins. Only one object may be identified and that must be a target object as specified in the BEGIN MLOAD command. |