table_name can be a simple table name or a full path name. A table name is preferred for portability to other SQL data sources.
col_name is the name of a column whose value is to be changed. Several columns can be changed in one statement.
expr is the new value for the column. The expression can be a constant value or a subquery. Character string values must be enclosed with single (’) or double (") quotation marks, date values must be enclosed by braces {}, and logical values that are letters must be enclosed by periods (for example, .T. or .F.). Subqueries must be enclosed in parentheses.
The Where Current Of cursor_name clause can be used only by developers coding directly to the ODBC API. It causes the row at which
cursor_name is positioned to be updated. This is called a "positioned update." You must first execute a Select...For Update statement with a named cursor and fetch the row to be updated.