LookUp()
LOOKUP() is a very cool, but very complex, way to pull information out of a table. It lets you look up information based on one field or tag, but return information from a different field. It's kind of like many of the lists and combo boxes we set up, where the user chooses based on one piece of data, but we store a different data item behind the scenes. Usage | uResult = LOOKUP( FieldToReturn, uSearchExpr, SearchField [, cSearchTag ] ) |
Parameter | Value | Meaning |
FieldToReturn | Name | The name of the field whose value is returned. |
uSearchExpr | Expression | The value to search for. |
SearchField | Name | The field in which to search for uSearchExpr unless cSearchTag is included. Ignored if cSearchTag is included; see below. |
cSearchTag | Character | The name of an index tag that should be used to search for uSearchExpr. |
Omitted | Search for uSearchExpr in the field SearchField. | |
uResult | Anything except empty value | The search expression was found, so the value of FieldToReturn for that record is returned. |
Empty | No record was found with the specified value. |
Example | USE Employee * No index used for this one ? LOOKUP(Birth_Date, "Laura", First_Name) && Returns {1/9/58} * Use name index. Specification of Last_Name is ignored, but * aids in readability ? LOOKUP(Home_Phone, "FULLER", Last_Name, "Last_Name") && Returns "(206) 555-9482" * Since there's an index on Employee_Id, it's used automatically ? LOOKUP(Last_Name, " 10", Employee_Id) && Returns "Martin" |
See Also | KeyMatch(), Locate, Seek, Seek() |
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Copyright © 2002 by Tamar E. Granor, Ted Roche, Doug Hennig, and Della Martin. All Rights Reserved.