DBCursorPrevious
Moves the cursor to the previous row of the result set and copies that row’s values to the mapped tags. If there is no previous row — that is, If the current row is the first — then the function returns an error code and doesn’t change the mapped tags.
| Function | Group | Execution | Windows | Embedded | Thin Client | Mobile Access |
|---|---|---|---|---|---|---|
| DBCursorPrevious | Database/ERP | Synchronous | Supported | Supported | Supported | Executed on Server |
Note: This feature emulates SQL (Structured Query Language) database operations. You should be familiar with how SQL commands are formed and executed before you use this feature.
Syntax
DBCursorPrevious( numCur, "optStrErrorTag" )
- numCur
- The cursor handle of the result set. The cursor handle is returned by DBCursorOpen or DBCursorOpenSQL.
- optStrErrorTag
- The name of a String tag that will receive detailed error messages, if errors occur during runtime.
Note: The tag name should be enclosed in quotes, as shown in the syntax diagram, or else the function will try to use the value of the tag.
This is an optional parameter.
Returned value
In case of error, returns a negative number. Otherwise, returns 0.
Notes
You can use the Studio Database Gateway to directly monitor database connections for leaks and errors. For more information, see Database Interface.
Examples
As used in a Math worksheet:
| Tag Name | Expression |
|---|---|
| nErrorCode | DBCursorPrevious( nCursor ) |