Difference between revisions of "lookup"
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== Definition == | == Definition == | ||
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Unit: FreePascal, unit '''db''' | Unit: FreePascal, unit '''db''' | ||
| − | <syntaxhighlight> | + | <syntaxhighlight lang=pascal> |
function Lookup(const KeyFields: string; const KeyValues: Variant; const ResultFields: string): Variant; | function Lookup(const KeyFields: string; const KeyValues: Variant; const ResultFields: string): Variant; | ||
</syntaxhighlight> | </syntaxhighlight> | ||
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== Description == | == Description == | ||
| − | '''lookup''' is similar to | + | |
| + | '''lookup''' is similar to [[locate]] in that it looks for a record in the dataset where the specified search values for the specified fields match. | ||
If found, the function returns a variant array with the values of the ResultFields (a semicolon-delimited list of desired fields). | If found, the function returns a variant array with the values of the ResultFields (a semicolon-delimited list of desired fields). | ||
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{{Note|Lookup is only implemented in non-unidirectional datasets, i.e. you must be able to move back and forwards through the dataset.}} | {{Note|Lookup is only implemented in non-unidirectional datasets, i.e. you must be able to move back and forwards through the dataset.}} | ||
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== See also == | == See also == | ||
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| − | [[ | + | * [[locate]] |
| − | [ | + | * [http://delphi.about.com/od/database/l/aa052901a.htm Description of how to use lookup with Delphi] |
Latest revision as of 06:55, 19 February 2020
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Definition
Unit: FreePascal, unit db
function Lookup(const KeyFields: string; const KeyValues: Variant; const ResultFields: string): Variant;
Official documentation: none
Description
lookup is similar to locate in that it looks for a record in the dataset where the specified search values for the specified fields match.
If found, the function returns a variant array with the values of the ResultFields (a semicolon-delimited list of desired fields). If not found, it returns Null. In neither case does it change the current physical record/cursor.
KeyFields can be a single field name or a semicolon-separated list of fields.
KeyValue can be a variant or a variant array and the number of items must match the number of fields specified in KeyFields.
Note: Lookup is only implemented in non-unidirectional datasets, i.e. you must be able to move back and forwards through the dataset.