INDEXES_MATCH_DEFSTRING Function
Syntax
Arguments
- Result
A pointer variable that contains the result. Result has the following properties:
- Property
Description
- .Error
.T. = an error occurred.
- .MissingIndexTags
A CR-LF delimited list of index tags that are missing from the table. The format is the same as Index_Definitions.
- .AdditionalIndexTags
A CR-LF delimited list of index tags that have been added to the table. Format is same as Index_Definitions.
- tablename
The name of the table containing the indexes.
- indexDefString
The index definitions as created by GET_INDEX_DEFINITIONS().
Description
Checks if a table's indexes match a Definition string (a crlf string of form Tagname|OrderExpn|FilterExpn|Flags). The definition string is typically created using Get_Index_Definitions(). Returns a pointer with these properties: Error (.t. or .f.), AdditionalIndexTags (tags in the table not in the index def), MissingIndexTags (tags in the index def, but not in the table).
Discussion
The INDEXES_MATCH_DEFSTRING() function checks the indexes in a table and compares them against a previously created index definition string. Allows you to tell if index tags are missing, or if index tags have been added. Used in conjunction with GET_INDEX_DEFINITIONS()and CREATE_INDEXES(), this function allows you to re-create the indexes for a table if they no longer match the required indexes.
Example
DIM indexDef as C
indexDef = get_index_definitions("customer")
? def
= Company|COMPANY||
Customer_Id|CUSTOMER_ID||
Customer_Id_Unique|CUSTOMER_ID||U
Lastname|LASTNAME+FIRSTNAME||
Lastname1|LASTNAME||Now edit the customer table, adding a new index tag on the bill_state_region field, and dropping the lastname1 index tag.
? indexes_match_defstring("customer", indexDef)
= AdditionalIndexTags = "STATE|BILL_STATE_REGION||"
Error = .F.
MissingIndexTags = "LASTNAME|LASTNAME+FIRSTNAME||"Recreate the indexes in the customer table so that they match the index definitions stored in indexDef.
? Create_Indexes("customer", indexDef)
= ErrorText = ""
HasError = .F.Check to see what indexes the customer table has.
? get_index_definitions("customer")
= Company|COMPANY||
Customer_Id|CUSTOMER_ID||
Customer_Id_Unique|CUSTOMER_ID||U
Lastname|LASTNAME+FIRSTNAME||
Lastname1|LASTNAME||See Also