====== U2_Btree_Extract subroutine     ======


 
==== Description ====
 
This subroutine is similar to the Linear Hash Btree.Extract.  Searches one or more indexes for data matching the search criteria passed in. Returns the keys to rows having matching data.
 
==== Syntax ====
 
U2_Btree_Extract(Search_String, Filename, Dictvar, Keys, Opts, Status)
 
==== Parameters ====
 
The subroutine has the following parameters:

^Parameter^Description^
|Search_String|The search criteria to use.  See Btree.Extract for syntax.\\ \\ Note: This is currently an exact match extract.|
|Filename|Pass the name of the file to be searched.|
|Dictvar|Pass the file handle for the dictionary of the specified file.|
|Keys|Returns row keys for all rows that satisfy the criteria in //Search_String//. Multiple keys are delimited with value marks.|
|Opts|For U2_Btree_Extract this parameter should be null.\\ \\ |
|Status|Error codes are returned in the Status parameter. After execution, keys contains a list of keys matching the search criteria. Status returns one of several possible values, depending on the success of the search process.\\ \\  __Value__ - __Meaning__\\ 0 - The search was successful. All possible keys were returned in //keys//.\\ -1 - The search failed, for reasons other than no keys found. This occurs, for example, when a specified column does not have a Btree index.|

 
==== See Also ====
 
[[btree.extract|Btree.Extract]], [[u2_functions_in_oi|U2 Functions]]