Lookup Function | |
-- todo --
Searches a table for the first record with a field matching the specified expression.
Namespace:
XSharp.VFP
Assembly:
XSharp.VFP (in XSharp.VFP.dll) Version: 2.21
Syntax FUNCTION Lookup(
ReturnField,
eSearchExpression,
SearchedField,
cTagName
) AS USUAL CLIPPER
[ClipperCallingConventionAttribute(new string[] { ... })]
public static Usual Lookup(
Usual ReturnField = default,
Usual eSearchExpression = default,
Usual SearchedField = default,
Usual cTagName = default
)
Request Example
View SourceParameters
- ReturnField (Optional)
- Type: Usual
- eSearchExpression (Optional)
- Type: Usual
- SearchedField (Optional)
- Type: Usual
- cTagName (Optional)
- Type: Usual
Return Value
Type:
Usual
Character, Numeric, Currency, Float, Integer, Double, Date, DateTime, or Logical.
Remarks
If the search is successful, LOOKUP( ) moves the record pointer to the matching record and
returns the contents of a specified field in the record.
If LOOKUP( ) does not find the search expression, it returns a blank value the same length and data type as ReturnField.
The record pointer is positioned at the end of the file.
If you use LOOKUP( ) to search a parent table, record pointers in all related child tables are moved to the related records.
This function cannot be optimized with Rushmore Query Optimization.
Examples 1Close Databases
2Open Database (HOME(2) + 'data\testdata')
3Use customer Order company
4Clear
5@ 2,2 SAY LOOKUP(contact, 'Ernst Handel', company, 'company')
See Also